diff --git a/packages/@n8n/api-types/src/schemas/policy-violation.schema.ts b/packages/@n8n/api-types/src/schemas/policy-violation.schema.ts
index c53a94413a1..2ffaeea7cd9 100644
--- a/packages/@n8n/api-types/src/schemas/policy-violation.schema.ts
+++ b/packages/@n8n/api-types/src/schemas/policy-violation.schema.ts
@@ -29,6 +29,15 @@ export const policyViolationSchema = z.object({
 
 	/** The rule that decided, if a rule did rather than a fallback default. */
 	matchedRuleId: z.string().optional(),
+
+	/**
+	 * The project whose policy was evaluated, also when `scope` is `'instance'`. For a
+	 * sub-workflow this is the sub-workflow's project, not the caller's.
+	 */
+	projectId: z.string().optional(),
+
+	/** The project can lift this block with its own allow rule. Absent means it cannot. */
+	optInAvailable: z.boolean().optional(),
 });
 
 export type PolicyViolation = z.infer<typeof policyViolationSchema>;
diff --git a/packages/cli/src/modules/type-availability-policies/README.md b/packages/cli/src/modules/type-availability-policies/README.md
index 17613dad6dd..504a294aa6f 100644
--- a/packages/cli/src/modules/type-availability-policies/README.md
+++ b/packages/cli/src/modules/type-availability-policies/README.md
@@ -166,13 +166,24 @@ One violation per blocked type, deduplicated, in the order the types first appea
 	"subject": "n8n-nodes-base.slack",
 	"subjectType": "nodeType",
 	"scope": "instance",
-	"matchedRuleId": "rule-7"
+	"matchedRuleId": "rule-7",
+	"projectId": "project-1",
+	"optInAvailable": false
 }
 ```
 
 `matchedRuleId` is absent when the scope's default action decided and no rule matched. `scope`
 names the scope whose verdict decided, which is what a user needs to know who to ask.
 
+`projectId` names the project whose policy was evaluated, also for an instance denial. A
+sub-workflow is checked against its own project, so its refusal names that project, not the
+caller's. It is absent when no project applied. A project denial's message says "a project
+policy" and never names the project: the client resolves the name, and only for a project the
+user can see.
+
+`optInAvailable` is `true` when the instance delegated the type, so the project can lift the
+block with its own allow rule. It is always `false` when no project applied.
+
 The violations reach the caller as HTTP 403 with `meta.violations`, and a blocked run stores
 them on the execution's error. Today that error is the whole story a user gets: the builder
 does not yet read `GET /projects/:projectId/available-types`, so a denied node looks normal
diff --git a/packages/cli/src/modules/type-availability-policies/__tests__/credential-type-policy.check.test.ts b/packages/cli/src/modules/type-availability-policies/__tests__/credential-type-policy.check.test.ts
index 267b3bb7eb7..deb30480056 100644
--- a/packages/cli/src/modules/type-availability-policies/__tests__/credential-type-policy.check.test.ts
+++ b/packages/cli/src/modules/type-availability-policies/__tests__/credential-type-policy.check.test.ts
@@ -651,6 +651,8 @@ describe('CredentialTypePolicyCheck', () => {
 				subjectType: 'credentialType',
 				scope: 'instance',
 				matchedRuleId: 'rule-7',
+				projectId: 'project-1',
+				optInAvailable: false,
 			});
 			expect(service.evaluateComposedTypesFor).toHaveBeenCalledWith(
 				'credential-types',
@@ -716,11 +718,13 @@ describe('CredentialTypePolicyCheck', () => {
 			expect(result.violations[0]).toStrictEqual({
 				kind: 'credential-type-unavailable',
 				checkId: 'credential-type-availability',
-				message: `Credential type "${SLACK_API}" is blocked by this project's policy`,
+				message: `Credential type "${SLACK_API}" is blocked by a project policy`,
 				subject: SLACK_API,
 				subjectType: 'credentialType',
 				scope: 'project',
 				matchedRuleId: 'rule-3',
+				projectId: 'project-1',
+				optInAvailable: false,
 			});
 		});
 
@@ -739,8 +743,54 @@ describe('CredentialTypePolicyCheck', () => {
 				subject: SLACK_API,
 				subjectType: 'credentialType',
 				scope: 'instance',
+				projectId: 'project-1',
+				optInAvailable: false,
 			});
 		});
+
+		it('carries the projectId from the context on a project-scope denial', async () => {
+			denying([SLACK_API], { scope: 'project' });
+
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK_NODE, { [SLACK_API]: 'cred-1' })]),
+				projectId: 'project-1',
+			});
+
+			expect(result.violations[0].projectId).toBe('project-1');
+		});
+
+		it('also carries the projectId on an instance-scope denial', async () => {
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK_NODE, { [SLACK_API]: 'cred-1' })]),
+				projectId: 'project-1',
+			});
+
+			expect(result.violations[0].scope).toBe('instance');
+			expect(result.violations[0].projectId).toBe('project-1');
+		});
+
+		it('reports optInAvailable true when the verdict allows it and a project applies', async () => {
+			denying([SLACK_API], { optInAvailable: true });
+
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK_NODE, { [SLACK_API]: 'cred-1' })]),
+				projectId: 'project-1',
+			});
+
+			expect(result.violations[0].optInAvailable).toBe(true);
+		});
+
+		it('drops projectId and forces optInAvailable false with no project, even when the verdict allows opt-in', async () => {
+			denying([SLACK_API], { optInAvailable: true });
+
+			const result = await check.onCredentialDecrypt({
+				...decryptOf(SLACK_API),
+				projectId: null,
+			});
+
+			expect(Object.keys(result.violations[0])).not.toContain('projectId');
+			expect(result.violations[0].optInAvailable).toBe(false);
+		});
 	});
 
 	describe('when the store is not worth reading', () => {
diff --git a/packages/cli/src/modules/type-availability-policies/__tests__/node-type-policy.check.test.ts b/packages/cli/src/modules/type-availability-policies/__tests__/node-type-policy.check.test.ts
index e50b2972878..8cb9aa2511e 100644
--- a/packages/cli/src/modules/type-availability-policies/__tests__/node-type-policy.check.test.ts
+++ b/packages/cli/src/modules/type-availability-policies/__tests__/node-type-policy.check.test.ts
@@ -228,6 +228,8 @@ describe('NodeTypePolicyCheck', () => {
 				subjectType: 'nodeType',
 				scope: 'instance',
 				matchedRuleId: 'rule-7',
+				projectId: 'project-1',
+				optInAvailable: false,
 			});
 			expect(service.evaluateComposedTypesFor).toHaveBeenCalledWith('node-types', 'project-1', [
 				SLACK,
@@ -297,11 +299,13 @@ describe('NodeTypePolicyCheck', () => {
 			expect(result.violations[0]).toStrictEqual({
 				kind: 'node-type-unavailable',
 				checkId: 'node-type-availability',
-				message: `Node type "${SLACK}" is blocked by this project's policy`,
+				message: `Node type "${SLACK}" is blocked by a project policy`,
 				subject: SLACK,
 				subjectType: 'nodeType',
 				scope: 'project',
 				matchedRuleId: 'rule-3',
+				projectId: 'project-1',
+				optInAvailable: false,
 			});
 		});
 
@@ -320,8 +324,64 @@ describe('NodeTypePolicyCheck', () => {
 				subject: SLACK,
 				subjectType: 'nodeType',
 				scope: 'instance',
+				projectId: 'project-1',
+				optInAvailable: false,
 			});
 		});
+
+		it('carries the projectId from the context on a project-scope denial', async () => {
+			denying([SLACK], { scope: 'project' });
+
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK)]),
+				projectId: 'project-1',
+			});
+
+			expect(result.violations[0].projectId).toBe('project-1');
+		});
+
+		it('also carries the projectId on an instance-scope denial', async () => {
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK)]),
+				projectId: 'project-1',
+			});
+
+			expect(result.violations[0].scope).toBe('instance');
+			expect(result.violations[0].projectId).toBe('project-1');
+		});
+
+		it('reports optInAvailable true when the verdict allows it and a project applies', async () => {
+			denying([SLACK], { optInAvailable: true });
+
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK)]),
+				projectId: 'project-1',
+			});
+
+			expect(result.violations[0].optInAvailable).toBe(true);
+		});
+
+		it('drops projectId and forces optInAvailable false with no project, even when the verdict allows opt-in', async () => {
+			denying([SLACK], { optInAvailable: true });
+
+			const result = await check.onContentImport({
+				workflow: workflow([node(SLACK)]),
+				projectId: null,
+				transport: 'cli',
+			});
+
+			expect(Object.keys(result.violations[0])).not.toContain('projectId');
+			expect(result.violations[0].optInAvailable).toBe(false);
+		});
+
+		it('names the projectId of the workflow-start context, as when a sub-workflow is checked against its own project', async () => {
+			const result = await check.onWorkflowStart({
+				workflow: workflow([node(SLACK)]),
+				projectId: 'sub-workflow-project',
+			});
+
+			expect(result.violations[0].projectId).toBe('sub-workflow-project');
+		});
 	});
 
 	describe('when the store is not worth reading', () => {
diff --git a/packages/cli/src/modules/type-availability-policies/credential-type-policy.check.ts b/packages/cli/src/modules/type-availability-policies/credential-type-policy.check.ts
index 58904f01559..a43a33fec4e 100644
--- a/packages/cli/src/modules/type-availability-policies/credential-type-policy.check.ts
+++ b/packages/cli/src/modules/type-availability-policies/credential-type-policy.check.ts
@@ -7,7 +7,6 @@ import type {
 	CredentialTransferContext,
 	PolicedWorkflow,
 	PolicyCheckResult,
-	PolicyViolation,
 	RegisteredPolicyCheck,
 	WorkflowPublishContext,
 	WorkflowSaveContext,
@@ -21,10 +20,8 @@ import { getActiveCredentialTypes } from 'n8n-workflow';
 import { NodeTypes } from '@/node-types';
 
 import { CREDENTIAL_TYPES_KIND } from './constants';
-import {
-	TypeAvailabilityPolicyService,
-	type ComposedTypeVerdict,
-} from './type-availability-policy.service';
+import { TypeAvailabilityPolicyService } from './type-availability-policy.service';
+import { CREDENTIAL_TYPE_SUBJECT, toTypeViolation } from './type-violation';
 
 const NO_VIOLATIONS: PolicyCheckResult = { violations: [] };
 
@@ -33,21 +30,6 @@ const NOTHING_GRANDFATHERED: ReadonlySet<string> = new Set();
 
 const CREDENTIAL_TYPE_PARAMETERS = ['nodeCredentialType', 'genericAuthType'] as const;
 
-function toViolation(checkId: string, verdict: ComposedTypeVerdict): PolicyViolation {
-	const by = verdict.scope === 'instance' ? 'an instance policy' : "this project's policy";
-
-	return {
-		kind: 'credential-type-unavailable',
-		checkId,
-		message: `Credential type "${verdict.name}" is blocked by ${by}`,
-		subject: verdict.name,
-		subjectType: 'credentialType',
-		scope: verdict.scope,
-		// The scope's default action decided when no rule matched, and there is no id to report.
-		...(verdict.matchedRuleId !== null && { matchedRuleId: verdict.matchedRuleId }),
-	};
-}
-
 /**
  * Enforces credential type availability policies, at every point that handles a workflow and
  * at both points that handle a credential.
@@ -241,7 +223,7 @@ export class CredentialTypePolicyCheck implements RegisteredPolicyCheck {
 		return {
 			violations: verdicts
 				.filter((verdict) => verdict.action === 'deny')
-				.map((verdict) => toViolation(this.id, verdict)),
+				.map((verdict) => toTypeViolation(this.id, CREDENTIAL_TYPE_SUBJECT, verdict, projectId)),
 			// Reported even when nothing is denied: the audit line records what a partial run read.
 			policyVersions: versions,
 		};
diff --git a/packages/cli/src/modules/type-availability-policies/node-type-policy.check.ts b/packages/cli/src/modules/type-availability-policies/node-type-policy.check.ts
index 9fc0ea9f502..5734804df5e 100644
--- a/packages/cli/src/modules/type-availability-policies/node-type-policy.check.ts
+++ b/packages/cli/src/modules/type-availability-policies/node-type-policy.check.ts
@@ -5,7 +5,6 @@ import type {
 	CredentialDecryptContext,
 	PolicedWorkflow,
 	PolicyCheckResult,
-	PolicyViolation,
 	RegisteredPolicyCheck,
 	WorkflowPublishContext,
 	WorkflowSaveContext,
@@ -15,10 +14,8 @@ import type {
 import { PolicyCheck } from '@n8n/decorators';
 
 import { NODE_TYPES_KIND } from './constants';
-import {
-	TypeAvailabilityPolicyService,
-	type ComposedTypeVerdict,
-} from './type-availability-policy.service';
+import { TypeAvailabilityPolicyService } from './type-availability-policy.service';
+import { NODE_TYPE_SUBJECT, toTypeViolation } from './type-violation';
 
 const NO_VIOLATIONS: PolicyCheckResult = { violations: [] };
 
@@ -30,21 +27,6 @@ function distinctTypes(nodes: PolicedWorkflow['nodes']): string[] {
 	return [...new Set(nodes.map((node) => node.type))];
 }
 
-function toViolation(checkId: string, verdict: ComposedTypeVerdict): PolicyViolation {
-	const by = verdict.scope === 'instance' ? 'an instance policy' : "this project's policy";
-
-	return {
-		kind: 'node-type-unavailable',
-		checkId,
-		message: `Node type "${verdict.name}" is blocked by ${by}`,
-		subject: verdict.name,
-		subjectType: 'nodeType',
-		scope: verdict.scope,
-		// The scope's default action decided when no rule matched, and there is no id to report.
-		...(verdict.matchedRuleId !== null && { matchedRuleId: verdict.matchedRuleId }),
-	};
-}
-
 /**
  * Enforces node type availability policies at every point that handles a workflow.
  *
@@ -157,7 +139,7 @@ export class NodeTypePolicyCheck implements RegisteredPolicyCheck {
 		return {
 			violations: verdicts
 				.filter((verdict) => verdict.action === 'deny')
-				.map((verdict) => toViolation(this.id, verdict)),
+				.map((verdict) => toTypeViolation(this.id, NODE_TYPE_SUBJECT, verdict, projectId)),
 			// Reported even when nothing is denied: the audit line records what a partial run read.
 			policyVersions: versions,
 		};
diff --git a/packages/cli/src/modules/type-availability-policies/type-violation.ts b/packages/cli/src/modules/type-availability-policies/type-violation.ts
new file mode 100644
index 00000000000..4231a6e5620
--- /dev/null
+++ b/packages/cli/src/modules/type-availability-policies/type-violation.ts
@@ -0,0 +1,46 @@
+import type { PolicyViolation } from '@n8n/decorators';
+
+import type { ComposedTypeVerdict } from './type-availability-policy.service';
+
+/** How one policy kind names what it blocked. */
+export type TypeViolationSubject = {
+	readonly kind: string;
+	readonly subjectType: string;
+	readonly label: string;
+};
+
+export const NODE_TYPE_SUBJECT: TypeViolationSubject = {
+	kind: 'node-type-unavailable',
+	subjectType: 'nodeType',
+	label: 'Node type',
+};
+
+export const CREDENTIAL_TYPE_SUBJECT: TypeViolationSubject = {
+	kind: 'credential-type-unavailable',
+	subjectType: 'credentialType',
+	label: 'Credential type',
+};
+
+/** The message stays neutral about which project: the client names it from `projectId`. */
+export function toTypeViolation(
+	checkId: string,
+	subject: TypeViolationSubject,
+	verdict: ComposedTypeVerdict,
+	projectId: string | null,
+): PolicyViolation {
+	const by = verdict.scope === 'instance' ? 'an instance policy' : 'a project policy';
+
+	return {
+		kind: subject.kind,
+		checkId,
+		message: `${subject.label} "${verdict.name}" is blocked by ${by}`,
+		subject: verdict.name,
+		subjectType: subject.subjectType,
+		scope: verdict.scope,
+		// The scope's default action decided when no rule matched, and there is no id to report.
+		...(verdict.matchedRuleId !== null && { matchedRuleId: verdict.matchedRuleId }),
+		...(projectId !== null && { projectId }),
+		// With no project there is nowhere to opt in, whatever the instance delegated.
+		optInAvailable: projectId !== null && verdict.optInAvailable,
+	};
+}
diff --git a/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/getSourceControlStatus.generated.yml b/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/getSourceControlStatus.generated.yml
index 6569bc009c2..b922e6c2087 100644
--- a/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/getSourceControlStatus.generated.yml
+++ b/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/getSourceControlStatus.generated.yml
@@ -143,6 +143,10 @@ responses:
                               type: string
                             matchedRuleId:
                               type: string
+                            projectId:
+                              type: string
+                            optInAvailable:
+                              type: boolean
                           required:
                             - kind
                             - checkId
diff --git a/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pullSourceControl.generated.yml b/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pullSourceControl.generated.yml
index c1002e339d7..029a0e9018c 100644
--- a/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pullSourceControl.generated.yml
+++ b/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pullSourceControl.generated.yml
@@ -153,6 +153,10 @@ responses:
                           type: string
                         matchedRuleId:
                           type: string
+                        projectId:
+                          type: string
+                        optInAvailable:
+                          type: boolean
                       required:
                         - kind
                         - checkId
@@ -310,6 +314,10 @@ responses:
                           type: string
                         matchedRuleId:
                           type: string
+                        projectId:
+                          type: string
+                        optInAvailable:
+                          type: boolean
                       required:
                         - kind
                         - checkId
diff --git a/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pushSourceControl.generated.yml b/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pushSourceControl.generated.yml
index c02d6fb4e28..861d154bdc2 100644
--- a/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pushSourceControl.generated.yml
+++ b/packages/cli/src/public-api/v1/handlers/source-control/spec/paths/pushSourceControl.generated.yml
@@ -173,6 +173,10 @@ responses:
                               type: string
                             matchedRuleId:
                               type: string
+                            projectId:
+                              type: string
+                            optInAvailable:
+                              type: boolean
                           required:
                             - kind
                             - checkId
@@ -337,6 +341,10 @@ responses:
                               type: string
                             matchedRuleId:
                               type: string
+                            projectId:
+                              type: string
+                            optInAvailable:
+                              type: boolean
                           required:
                             - kind
                             - checkId
diff --git a/packages/cli/src/public-api/v1/shared/spec/schemas/importBlockingIssue.generated.yml b/packages/cli/src/public-api/v1/shared/spec/schemas/importBlockingIssue.generated.yml
index 7fd9ecbc6f2..1b5a5f485b2 100644
--- a/packages/cli/src/public-api/v1/shared/spec/schemas/importBlockingIssue.generated.yml
+++ b/packages/cli/src/public-api/v1/shared/spec/schemas/importBlockingIssue.generated.yml
@@ -652,6 +652,10 @@ oneOf:
               type: string
             matchedRuleId:
               type: string
+            projectId:
+              type: string
+            optInAvailable:
+              type: boolean
           required:
             - kind
             - checkId
@@ -699,6 +703,10 @@ oneOf:
               type: string
             matchedRuleId:
               type: string
+            projectId:
+              type: string
+            optInAvailable:
+              type: boolean
           required:
             - kind
             - checkId
diff --git a/packages/cli/src/public-api/v1/shared/spec/schemas/policyViolation.yml b/packages/cli/src/public-api/v1/shared/spec/schemas/policyViolation.yml
index 38a4133312c..776604696e9 100644
--- a/packages/cli/src/public-api/v1/shared/spec/schemas/policyViolation.yml
+++ b/packages/cli/src/public-api/v1/shared/spec/schemas/policyViolation.yml
@@ -29,3 +29,11 @@ properties:
   matchedRuleId:
     type: string
     description: The rule that decided, if a rule did rather than a fallback default.
+  projectId:
+    type: string
+    description: >
+      The project whose policy was evaluated, also when `scope` is `instance`. For a
+      sub-workflow this is the sub-workflow's project, not the caller's.
+  optInAvailable:
+    type: boolean
+    description: The project can lift this block with its own allow rule. Absent means it cannot.
diff --git a/packages/cli/src/utils/__tests__/object-to-error.test.ts b/packages/cli/src/utils/__tests__/object-to-error.test.ts
index 1256eebfe12..a7656cdf076 100644
--- a/packages/cli/src/utils/__tests__/object-to-error.test.ts
+++ b/packages/cli/src/utils/__tests__/object-to-error.test.ts
@@ -40,4 +40,40 @@ describe('objectToError', () => {
 			expect(result.message).toBe('Test error');
 		});
 	});
+
+	describe('policy violations', () => {
+		it('should copy `violations` from the error object', () => {
+			const violation = {
+				kind: 'node-type-unavailable',
+				checkId: 'node-type-availability',
+				message: 'Node type "n8n-nodes-base.set" is blocked by a project policy',
+				subject: 'n8n-nodes-base.set',
+				subjectType: 'nodeType',
+				scope: 'project',
+				projectId: 'project-1',
+				optInAvailable: false,
+			};
+			const errorObject = {
+				message: 'Test error',
+				violations: [violation],
+			};
+			const workflow = mock<Workflow>();
+
+			const result = objectToError(errorObject, workflow);
+
+			expect((result as unknown as { violations: unknown[] }).violations).toEqual([violation]);
+		});
+
+		it('should not copy `isPolicyRefusal`', () => {
+			const errorObject = {
+				message: 'Test error',
+				isPolicyRefusal: true,
+			};
+			const workflow = mock<Workflow>();
+
+			const result = objectToError(errorObject, workflow);
+
+			expect(Object.hasOwn(result, 'isPolicyRefusal')).toBe(false);
+		});
+	});
 });
diff --git a/packages/cli/src/utils/object-to-error.ts b/packages/cli/src/utils/object-to-error.ts
index 9fb6d57ed5e..fc2157afdea 100644
--- a/packages/cli/src/utils/object-to-error.ts
+++ b/packages/cli/src/utils/object-to-error.ts
@@ -4,8 +4,11 @@ import type { Workflow } from 'n8n-workflow';
 
 /**
  * Optional properties that should be propagated from an error object to the new Error instance.
+ *
+ * `violations` keeps a sub-workflow's policy refusal readable in the parent. The
+ * `isPolicyRefusal` marker is left out: the parent's own graph was not refused.
  */
-const errorProperties = ['description', 'stack', 'executionId', 'workflowId'];
+const errorProperties = ['description', 'stack', 'executionId', 'workflowId', 'violations'];
 
 export function objectToError(errorObject: unknown, workflow: Workflow): Error {
 	// TODO: Expand with other error types
diff --git a/packages/cli/test/integration/policy/credential-type-policy.credential-save.test.ts b/packages/cli/test/integration/policy/credential-type-policy.credential-save.test.ts
index 40c81a9fd97..99d5e38654e 100644
--- a/packages/cli/test/integration/policy/credential-type-policy.credential-save.test.ts
+++ b/packages/cli/test/integration/policy/credential-type-policy.credential-save.test.ts
@@ -3,7 +3,12 @@
  * while a credential that predates the rule stays editable. The lock belongs at decryption,
  * so the refusal here is about not letting someone set up what can never work.
  */
-import { createTeamProject, randomCredentialPayload, testDb } from '@n8n/backend-test-utils';
+import {
+	createTeamProject,
+	getPersonalProject,
+	randomCredentialPayload,
+	testDb,
+} from '@n8n/backend-test-utils';
 import { LICENSE_FEATURES } from '@n8n/constants';
 import { CredentialsRepository, type User } from '@n8n/db';
 import { PolicyCheckMetadata } from '@n8n/decorators';
@@ -38,14 +43,21 @@ let credentialsRepository: CredentialsRepository;
 const denyGithubAtInstanceScope = async () =>
 	await putCredentialTypePolicy(ownerAgent, null, { rules: [denyRule('deny-github', BLOCKED)] });
 
-const violationFor = (credentialType: string, scope: 'instance' | 'project', ruleId: string) => ({
+const violationFor = (
+	credentialType: string,
+	scope: 'instance' | 'project',
+	ruleId: string,
+	{ projectId, optInAvailable = false }: { projectId?: string; optInAvailable?: boolean } = {},
+) => ({
 	kind: 'credential-type-unavailable',
 	checkId: CHECK_ID,
-	message: `Credential type "${credentialType}" is blocked by ${scope === 'instance' ? 'an instance policy' : "this project's policy"}`,
+	message: `Credential type "${credentialType}" is blocked by ${scope === 'instance' ? 'an instance policy' : 'a project policy'}`,
 	subject: credentialType,
 	subjectType: 'credentialType',
 	scope,
 	matchedRuleId: ruleId,
+	...(projectId !== undefined && { projectId }),
+	optInAvailable,
 });
 
 beforeAll(async () => {
@@ -111,7 +123,7 @@ describe('POST /credentials', () => {
 			.expect(403);
 
 		expect(response.body.meta.violations).toEqual([
-			violationFor(BLOCKED, 'project', 'deny-github'),
+			violationFor(BLOCKED, 'project', 'deny-github', { projectId: project.id }),
 		]);
 		await expect(credentialsRepository.count()).resolves.toBe(0);
 	});
@@ -147,8 +159,9 @@ describe('PATCH /credentials/:credentialId', () => {
 			.send({ ...randomCredentialPayload({ type: BLOCKED }), name: credential.name })
 			.expect(403);
 
+		const { id: projectId } = await getPersonalProject(owner);
 		expect(response.body.meta.violations).toEqual([
-			violationFor(BLOCKED, 'instance', 'deny-github'),
+			violationFor(BLOCKED, 'instance', 'deny-github', { projectId }),
 		]);
 
 		const stored = await credentialsRepository.findOneBy({ id: credential.id });
diff --git a/packages/cli/test/integration/policy/credential-type-policy.extends.test.ts b/packages/cli/test/integration/policy/credential-type-policy.extends.test.ts
index d9967807b16..73a34fd05f1 100644
--- a/packages/cli/test/integration/policy/credential-type-policy.extends.test.ts
+++ b/packages/cli/test/integration/policy/credential-type-policy.extends.test.ts
@@ -2,7 +2,12 @@
  * Pins what an `extends` rule decides for real host paths: a rule on a base credential type
  * refuses a workflow that asks for a type built on it, exactly as a rule on that type would.
  */
-import { createWorkflow, randomCredentialPayload, testDb } from '@n8n/backend-test-utils';
+import {
+	createWorkflow,
+	getPersonalProject,
+	randomCredentialPayload,
+	testDb,
+} from '@n8n/backend-test-utils';
 import type { PolicyRule } from '@n8n/api-types';
 import { LICENSE_FEATURES } from '@n8n/constants';
 import { ExecutionRepository, WorkflowRepository, type User } from '@n8n/db';
@@ -65,7 +70,7 @@ const workflowBody = () => ({
 	connections: {},
 });
 
-const derivedViolation = {
+const derivedViolation = (projectId: string) => ({
 	kind: 'credential-type-unavailable',
 	checkId: 'credential-type-availability',
 	message: `Credential type "${DERIVED}" is blocked by an instance policy`,
@@ -73,7 +78,9 @@ const derivedViolation = {
 	subjectType: 'credentialType',
 	scope: 'instance',
 	matchedRuleId: 'deny-oauth2-family',
-};
+	projectId,
+	optInAvailable: false,
+});
 
 beforeAll(async () => {
 	await utils.initNodeTypes();
@@ -120,7 +127,8 @@ describe('a rule on a base credential type', () => {
 
 		const response = await ownerAgent.post('/workflows').send(workflowBody()).expect(403);
 
-		expect(response.body.meta.violations).toEqual([derivedViolation]);
+		const { id: projectId } = await getPersonalProject(owner);
+		expect(response.body.meta.violations).toEqual([derivedViolation(projectId)]);
 		await expect(workflowRepository.count()).resolves.toBe(0);
 	});
 
@@ -150,7 +158,8 @@ describe('a rule on a base credential type', () => {
 		});
 		const error = stored?.data.resultData.error as unknown as { violations?: unknown[] };
 
-		expect(error?.violations).toEqual([derivedViolation]);
+		const { id: projectId } = await getPersonalProject(owner);
+		expect(error?.violations).toEqual([derivedViolation(projectId)]);
 	});
 
 	test('lets an earlier allow for the derived type win over the family deny', async () => {
diff --git a/packages/cli/test/integration/policy/credential-type-policy.workflow.test.ts b/packages/cli/test/integration/policy/credential-type-policy.workflow.test.ts
index 37f3c0b0f3c..46a9e0b1c7f 100644
--- a/packages/cli/test/integration/policy/credential-type-policy.workflow.test.ts
+++ b/packages/cli/test/integration/policy/credential-type-policy.workflow.test.ts
@@ -10,6 +10,7 @@ import {
 	createTeamProject,
 	createWorkflow,
 	createWorkflowWithHistory,
+	getPersonalProject,
 	randomCredentialPayload,
 	testDb,
 } from '@n8n/backend-test-utils';
@@ -103,14 +104,17 @@ const violationFor = (
 	credentialType: string,
 	scope: 'instance' | 'project',
 	matchedRuleId: string,
+	{ projectId, optInAvailable = false }: { projectId?: string; optInAvailable?: boolean } = {},
 ) => ({
 	kind: 'credential-type-unavailable',
 	checkId: CHECK_ID,
-	message: `Credential type "${credentialType}" is blocked by ${scope === 'instance' ? 'an instance policy' : "this project's policy"}`,
+	message: `Credential type "${credentialType}" is blocked by ${scope === 'instance' ? 'an instance policy' : 'a project policy'}`,
 	subject: credentialType,
 	subjectType: 'credentialType',
 	scope,
 	matchedRuleId,
+	...(projectId !== undefined && { projectId }),
+	optInAvailable,
 });
 
 type CredentialOwner = Parameters<typeof saveCredential>[1];
@@ -248,8 +252,9 @@ describe('saving a workflow', () => {
 			})
 			.expect(403);
 
+		const { id: projectId } = await getPersonalProject(owner);
 		expect(response.body.meta.violations).toEqual([
-			violationFor(BLOCKED, 'instance', 'deny-github'),
+			violationFor(BLOCKED, 'instance', 'deny-github', { projectId }),
 		]);
 		await expect(workflowRepository.count()).resolves.toBe(0);
 	});
@@ -286,8 +291,9 @@ describe('saving a workflow', () => {
 			.send({ name: 'New workflow', nodes: [node(MANUAL_TRIGGER), inlineAgent], connections: {} })
 			.expect(403);
 
+		const { id: projectId } = await getPersonalProject(owner);
 		expect(response.body.meta.violations).toEqual([
-			violationFor(BLOCKED, 'instance', 'deny-github'),
+			violationFor(BLOCKED, 'instance', 'deny-github', { projectId }),
 		]);
 		await expect(workflowRepository.count()).resolves.toBe(0);
 	});
@@ -387,7 +393,10 @@ describe('starting a run', () => {
 		});
 		const error = stored?.data.resultData.error as unknown as { violations?: unknown[] };
 
-		expect(error?.violations).toEqual([violationFor(BLOCKED, 'instance', 'deny-github')]);
+		const { id: projectId } = await getPersonalProject(owner);
+		expect(error?.violations).toEqual([
+			violationFor(BLOCKED, 'instance', 'deny-github', { projectId }),
+		]);
 	});
 
 	test('runs as usual when no rule matches', async () => {
@@ -423,7 +432,9 @@ describe('PUT /workflows/:workflowId/transfer', () => {
 
 		expect(response.body).toMatchObject({
 			code: 403,
-			meta: { violations: [violationFor(BLOCKED, 'project', 'deny-github')] },
+			meta: {
+				violations: [violationFor(BLOCKED, 'project', 'deny-github', { projectId: project.id })],
+			},
 		});
 	});
 
diff --git a/packages/cli/test/integration/policy/node-type-policy.publish-and-start.test.ts b/packages/cli/test/integration/policy/node-type-policy.publish-and-start.test.ts
index 9866f74eb0c..73f9f63794d 100644
--- a/packages/cli/test/integration/policy/node-type-policy.publish-and-start.test.ts
+++ b/packages/cli/test/integration/policy/node-type-policy.publish-and-start.test.ts
@@ -6,7 +6,12 @@
  * behaviour the RFC asks for and the one users will call a bug — "my old workflow saves but
  * will not run" — so it is worth pinning on the real paths rather than in the check's own tests.
  */
-import { createWorkflow, createWorkflowWithHistory, testDb } from '@n8n/backend-test-utils';
+import {
+	createWorkflow,
+	createWorkflowWithHistory,
+	getPersonalProject,
+	testDb,
+} from '@n8n/backend-test-utils';
 import { WorkflowsConfig } from '@n8n/config';
 import { LICENSE_FEATURES } from '@n8n/constants';
 import { ExecutionRepository, WorkflowRepository, type IWorkflowDb, type User } from '@n8n/db';
@@ -97,6 +102,7 @@ const expectedViolation = {
 	subjectType: 'nodeType',
 	scope: 'instance',
 	matchedRuleId: 'deny-set',
+	optInAvailable: false,
 };
 
 beforeAll(async () => {
@@ -254,7 +260,8 @@ describe('starting a run', () => {
 			violations?: unknown[];
 		};
 
-		expect(error?.violations).toEqual([expectedViolation]);
+		const { id: projectId } = await getPersonalProject(owner);
+		expect(error?.violations).toEqual([{ ...expectedViolation, projectId }]);
 	});
 
 	test('fails the run of a workflow whose inline agent has a blocked node tool', async () => {
@@ -273,7 +280,8 @@ describe('starting a run', () => {
 			unflattenData: true,
 		});
 		const error = stored?.data.resultData.error as unknown as { violations?: unknown[] };
-		expect(error?.violations).toEqual([expectedViolation]);
+		const { id: projectId } = await getPersonalProject(owner);
+		expect(error?.violations).toEqual([{ ...expectedViolation, projectId }]);
 	});
 
 	test('runs as usual when no rule matches the workflow', async () => {
diff --git a/packages/cli/test/integration/policy/node-type-policy.save.test.ts b/packages/cli/test/integration/policy/node-type-policy.save.test.ts
index ce35f0c1ca7..1200686cbf9 100644
--- a/packages/cli/test/integration/policy/node-type-policy.save.test.ts
+++ b/packages/cli/test/integration/policy/node-type-policy.save.test.ts
@@ -7,7 +7,13 @@
  * to be an integration test: it depends on the stored workflow the host loads, which no unit
  * test supplies for real.
  */
-import { createTeamProject, createWorkflow, mockInstance, testDb } from '@n8n/backend-test-utils';
+import {
+	createTeamProject,
+	createWorkflow,
+	getPersonalProject,
+	mockInstance,
+	testDb,
+} from '@n8n/backend-test-utils';
 import { LICENSE_FEATURES } from '@n8n/constants';
 import { WorkflowRepository, type Project, type User } from '@n8n/db';
 import { PolicyCheckMetadata } from '@n8n/decorators';
@@ -94,14 +100,21 @@ async function putProjectPolicy(
 	return response.body as { version: number };
 }
 
-const violationFor = (typeName: string, scope: 'instance' | 'project', matchedRuleId: string) => ({
+const violationFor = (
+	typeName: string,
+	scope: 'instance' | 'project',
+	matchedRuleId: string,
+	{ projectId, optInAvailable = false }: { projectId?: string; optInAvailable?: boolean } = {},
+) => ({
 	kind: 'node-type-unavailable',
 	checkId: CHECK_ID,
-	message: `Node type "${typeName}" is blocked by ${scope === 'instance' ? 'an instance policy' : "this project's policy"}`,
+	message: `Node type "${typeName}" is blocked by ${scope === 'instance' ? 'an instance policy' : 'a project policy'}`,
 	subject: typeName,
 	subjectType: 'nodeType',
 	scope,
 	matchedRuleId,
+	...(projectId !== undefined && { projectId }),
+	optInAvailable,
 });
 
 beforeAll(async () => {
@@ -316,9 +329,10 @@ describe('POST /workflows', () => {
 			})
 			.expect(403);
 
+		const { id: projectId } = await getPersonalProject(owner);
 		expect(response.body.meta.violations).toEqual([
-			violationFor(SET, 'instance', 'deny-set'),
-			violationFor(SCHEDULE_TRIGGER, 'instance', 'deny-schedule'),
+			violationFor(SET, 'instance', 'deny-set', { projectId }),
+			violationFor(SCHEDULE_TRIGGER, 'instance', 'deny-schedule', { projectId }),
 		]);
 	});
 });
@@ -338,7 +352,7 @@ describe('PUT /workflows/:workflowId/transfer', () => {
 
 		expect(response.body).toMatchObject({
 			code: 403,
-			meta: { violations: [violationFor(SET, 'project', 'deny-set')] },
+			meta: { violations: [violationFor(SET, 'project', 'deny-set', { projectId: project.id })] },
 		});
 	});
 
@@ -382,7 +396,12 @@ describe('instance and project scope composition', () => {
 
 		const response = await saveWithSet().expect(403);
 
-		expect(response.body.meta.violations).toEqual([violationFor(SET, 'instance', 'delegate-set')]);
+		expect(response.body.meta.violations).toEqual([
+			violationFor(SET, 'instance', 'delegate-set', {
+				projectId: project.id,
+				optInAvailable: true,
+			}),
+		]);
 	});
 
 	test('keeps an instance deny in force over a project allow', async () => {
@@ -391,6 +410,8 @@ describe('instance and project scope composition', () => {
 
 		const response = await saveWithSet().expect(403);
 
-		expect(response.body.meta.violations).toEqual([violationFor(SET, 'instance', 'deny-set')]);
+		expect(response.body.meta.violations).toEqual([
+			violationFor(SET, 'instance', 'deny-set', { projectId: project.id }),
+		]);
 	});
 });
diff --git a/packages/cli/test/integration/policy/node-type-policy.sub-workflow.test.ts b/packages/cli/test/integration/policy/node-type-policy.sub-workflow.test.ts
new file mode 100644
index 00000000000..68e57a92f06
--- /dev/null
+++ b/packages/cli/test/integration/policy/node-type-policy.sub-workflow.test.ts
@@ -0,0 +1,136 @@
+/**
+ * Pins whose project a sub-workflow refusal names. The child is checked against its own
+ * project's policy, and that refusal travels up to the parent's execution unchanged.
+ */
+import { createTeamProject, createWorkflow, testDb } from '@n8n/backend-test-utils';
+import { LICENSE_FEATURES } from '@n8n/constants';
+import { ExecutionRepository, type IWorkflowDb, type Project, type User } from '@n8n/db';
+import { Container } from '@n8n/di';
+import { v4 as uuid } from 'uuid';
+
+import { createOwner } from '../shared/db/users';
+import type { SuperAgentTest } from '../shared/types';
+import * as utils from '../shared/utils/';
+import { loadNodesFromDist } from '../shared/utils/node-types-data';
+import { createParentWorkflowFixture, createSubWorkflowFixture } from '../shared/workflow-fixtures';
+import { clearPolicyCache } from './shared/policy-cache';
+
+const SET = 'n8n-nodes-base.set';
+
+const testServer = utils.setupTestServer({
+	endpointGroups: ['workflows', 'executions', 'type-availability-policies'],
+	modules: ['policy-infrastructure', 'type-availability-policies'],
+	enabledFeatures: [LICENSE_FEATURES.TYPE_AVAILABILITY_POLICIES],
+});
+
+let owner: User;
+let ownerAgent: SuperAgentTest;
+let childProject: Project;
+let executionRepository: ExecutionRepository;
+
+beforeAll(async () => {
+	await utils.initNodeTypes(
+		loadNodesFromDist([
+			'n8n-nodes-base.manualTrigger',
+			'n8n-nodes-base.executeWorkflow',
+			'n8n-nodes-base.executeWorkflowTrigger',
+			SET,
+		]),
+	);
+	await utils.initBinaryDataService();
+
+	owner = await createOwner();
+	ownerAgent = testServer.authAgentFor(owner);
+	executionRepository = Container.get(ExecutionRepository);
+});
+
+beforeEach(async () => {
+	childProject = await createTeamProject('Child project', owner);
+});
+
+afterEach(async () => {
+	await testDb.truncate([
+		'TypeAvailabilityPolicyAttachment',
+		'TypeAvailabilityPolicyScope',
+		'TypeAvailabilityPolicy',
+		'ExecutionEntity',
+		'WorkflowEntity',
+		'SharedWorkflow',
+	]);
+	await clearPolicyCache();
+});
+
+async function waitForFinalStatus(executionId: string, timeout = 20000) {
+	const start = Date.now();
+
+	while (Date.now() - start < timeout) {
+		const execution = await executionRepository.findOne({ where: { id: executionId } });
+		if (execution && ['error', 'success', 'crashed'].includes(execution.status)) {
+			return execution;
+		}
+		await new Promise((resolve) => setTimeout(resolve, 50));
+	}
+
+	throw new Error(`Execution ${executionId} did not finish within ${timeout}ms`);
+}
+
+test("names the sub-workflow's project when that project blocks a node", async () => {
+	const childFixture = createSubWorkflowFixture();
+	const child = await createWorkflow(
+		{
+			name: 'Child',
+			...childFixture,
+			// Unconnected: the check reads the node list, so the node never has to run.
+			nodes: [
+				...childFixture.nodes,
+				{
+					id: uuid(),
+					name: 'Set',
+					type: SET,
+					typeVersion: 3.4,
+					position: [200, 0],
+					parameters: {},
+				},
+			],
+			settings: { callerPolicy: 'any' },
+		} as unknown as IWorkflowDb,
+		childProject,
+	);
+	const parent = await createWorkflow(
+		{ name: 'Parent', ...createParentWorkflowFixture(child.id) } as unknown as IWorkflowDb,
+		owner,
+	);
+
+	await ownerAgent
+		.put(`/projects/${childProject.id}/node-type-policies/project`)
+		.send({
+			rules: [{ id: 'deny-set', action: 'deny', selector: { kind: 'name', value: SET } }],
+			defaultAction: 'allow',
+			version: 0,
+		})
+		.expect(200);
+
+	const response = await ownerAgent
+		.post(`/workflows/${parent.id}/run`)
+		.send({ triggerToStartFrom: { name: 'Trigger' } })
+		.expect(200);
+	const parentExecutionId = response.body.data.executionId as string;
+
+	const execution = await waitForFinalStatus(parentExecutionId);
+	expect(execution.status).toBe('error');
+
+	const stored = await executionRepository.findSingleExecution(parentExecutionId, {
+		includeData: true,
+		unflattenData: true,
+	});
+	const error = stored?.data.resultData.error as unknown as { violations?: unknown[] };
+
+	expect(error?.violations).toEqual([
+		expect.objectContaining({
+			subject: SET,
+			scope: 'project',
+			projectId: childProject.id,
+			optInAvailable: false,
+		}),
+	]);
+});