diff --git a/apps/server/.env.example b/apps/server/.env.example
index f45244d..1837c5c 100644
--- a/apps/server/.env.example
+++ b/apps/server/.env.example
@@ -46,6 +46,7 @@ DEMO_INTAKE_RATE_LIMIT_MAX=10
 
 # Optional real extraction
 OPENROUTER_API_KEY=
+EXTRACTION_API_URL=https://openrouter.ai/api/v1/chat/completions
 OPENROUTER_PRIMARY_MODEL=
 OPENROUTER_FALLBACK_MODEL=
 OPENROUTER_TIMEOUT_MS=60000
diff --git a/apps/server/src/adapters/extraction/openrouter-extraction-adapter.test.ts b/apps/server/src/adapters/extraction/openrouter-extraction-adapter.test.ts
index 04562c5..b44f7fc 100644
--- a/apps/server/src/adapters/extraction/openrouter-extraction-adapter.test.ts
+++ b/apps/server/src/adapters/extraction/openrouter-extraction-adapter.test.ts
@@ -4,6 +4,7 @@ import type { PreparedPage } from '../documents/document-preparation.js';
 
 import {
   OpenRouterExtractionAdapter,
+  createOpenRouterConfig,
   type OpenRouterConfig
 } from './openrouter-extraction-adapter.js';
 import type { ExtractionCallResult } from './openrouter-extraction-adapter.js';
@@ -50,6 +51,7 @@ function makePages(): PreparedPage[] {
 function makeConfig(overrides: Partial<OpenRouterConfig> = {}): OpenRouterConfig {
   return {
     apiKey: 'test-key',
+    apiUrl: 'https://openrouter.example.test/v1/chat/completions',
     primaryModel: 'google/gemini-2.5-flash',
     fallbackModel: 'openai/gpt-4o',
     timeoutMs: 5_000,
@@ -91,6 +93,16 @@ describe('OpenRouterExtractionAdapter', () => {
     vi.restoreAllMocks();
   });
 
+  it('reads a configurable extraction API URL', () => {
+    expect(
+      createOpenRouterConfig({
+        OPENROUTER_API_KEY: 'test-key',
+        EXTRACTION_API_URL:
+          'https://generativelanguage.googleapis.com/v1beta/openai/chat/completions'
+      }).apiUrl
+    ).toBe('https://generativelanguage.googleapis.com/v1beta/openai/chat/completions');
+  });
+
   it('extracts invoice from primary model successfully', async () => {
     const fetchMock = vi
       .fn()
@@ -105,6 +117,9 @@ describe('OpenRouterExtractionAdapter', () => {
     expect(result.metadata.fallbackUsed).toBe(false);
     expect(result.metadata.promptVersion).toBe('invoice-extraction-v1');
     expect(fetchMock).toHaveBeenCalledTimes(1);
+    expect(fetchMock.mock.calls[0]?.[0]).toBe(
+      'https://openrouter.example.test/v1/chat/completions'
+    );
   });
 
   it('falls back when primary returns invalid schema', async () => {
diff --git a/apps/server/src/adapters/extraction/openrouter-extraction-adapter.ts b/apps/server/src/adapters/extraction/openrouter-extraction-adapter.ts
index b4e7a9b..8cd3e2d 100644
--- a/apps/server/src/adapters/extraction/openrouter-extraction-adapter.ts
+++ b/apps/server/src/adapters/extraction/openrouter-extraction-adapter.ts
@@ -5,10 +5,11 @@ import type { PreparedPage } from '../documents/document-preparation.js';
 import { SYSTEM_PROMPT, PROMPT_VERSION } from './extraction-prompt.js';
 import { parseExtractedInvoice } from './extraction-schema.js';
 
-const OPENROUTER_URL = 'https://openrouter.ai/api/v1/chat/completions';
+const DEFAULT_EXTRACTION_API_URL = 'https://openrouter.ai/api/v1/chat/completions';
 
 export interface OpenRouterConfig {
   apiKey: string;
+  apiUrl: string;
   primaryModel: string;
   fallbackModel: string;
   timeoutMs: number;
@@ -102,7 +103,7 @@ export class OpenRouterExtractionAdapter {
     const timeoutId = setTimeout(() => controller.abort(), this.config.timeoutMs);
 
     try {
-      const response = await fetch(OPENROUTER_URL, {
+      const response = await fetch(this.config.apiUrl, {
         method: 'POST',
         headers: {
           Authorization: `Bearer ${this.config.apiKey}`,
@@ -191,6 +192,7 @@ export function createOpenRouterConfig(env: NodeJS.ProcessEnv = process.env): Op
   }
   return {
     apiKey,
+    apiUrl: env.EXTRACTION_API_URL ?? DEFAULT_EXTRACTION_API_URL,
     primaryModel: env.OPENROUTER_PRIMARY_MODEL ?? 'google/gemini-2.5-flash',
     fallbackModel: env.OPENROUTER_FALLBACK_MODEL ?? 'openai/gpt-4o',
     timeoutMs: Number(env.OPENROUTER_TIMEOUT_MS ?? 60_000),
diff --git a/apps/server/src/domain/invoice-cases/invoice-case.test.ts b/apps/server/src/domain/invoice-cases/invoice-case.test.ts
index 6e41c17..75a9864 100644
--- a/apps/server/src/domain/invoice-cases/invoice-case.test.ts
+++ b/apps/server/src/domain/invoice-cases/invoice-case.test.ts
@@ -15,6 +15,7 @@ import {
   financeDecision,
   recordFindings,
   rejectInvoiceCase,
+  retryPosting,
   requestReprocessing,
   resolveFinding,
   transitionInvoiceCase,
@@ -221,6 +222,26 @@ describe('Invoice Case authority', () => {
       DomainRuleError
     );
   });
+
+  it('retries a failed posting with the AP owner and current version', () => {
+    const readyToPost = confirmAp(reviewCase(), { expectedVersion: 2, actor: owner });
+    const posting = beginPosting(readyToPost, { expectedVersion: 3, actor: owner });
+    const failed = transitionInvoiceCase(posting, {
+      expectedVersion: 4,
+      to: 'posting_failed'
+    });
+
+    expect(retryPosting(failed, { expectedVersion: 5, actor: owner })).toMatchObject({
+      state: 'posting',
+      version: 6
+    });
+    expect(() => retryPosting(failed, { expectedVersion: 4, actor: owner })).toThrowError(
+      DomainRuleError
+    );
+    expect(() => retryPosting(failed, { expectedVersion: 5, actor: finance })).toThrowError(
+      DomainRuleError
+    );
+  });
 });
 
 describe('Invoice Draft revisions and validation', () => {
diff --git a/apps/server/src/domain/invoice-cases/invoice-case.ts b/apps/server/src/domain/invoice-cases/invoice-case.ts
index 4bab85f..2f9b549 100644
--- a/apps/server/src/domain/invoice-cases/invoice-case.ts
+++ b/apps/server/src/domain/invoice-cases/invoice-case.ts
@@ -338,6 +338,20 @@ export function beginPosting(
   return updateCase(invoiceCase, { state: 'posting' });
 }
 
+export function retryPosting(
+  invoiceCase: InvoiceCase,
+  input: { expectedVersion: number; actor: InvoiceCaseActor }
+): InvoiceCase {
+  assertMutable(invoiceCase);
+  assertVersion(invoiceCase, input.expectedVersion);
+  assertApOwner(invoiceCase, input.actor, 'invoice.post');
+  if (invoiceCase.state !== 'posting_failed') {
+    throw new DomainRuleError('invalid_transition', 'Case is not waiting for posting retry');
+  }
+
+  return updateCase(invoiceCase, { state: 'posting' });
+}
+
 export function completePosting(
   invoiceCase: InvoiceCase,
   input: { expectedVersion: number }
diff --git a/apps/server/src/repositories/invoice-case.repository.ts b/apps/server/src/repositories/invoice-case.repository.ts
index 82f9dfa..a39e09c 100644
--- a/apps/server/src/repositories/invoice-case.repository.ts
+++ b/apps/server/src/repositories/invoice-case.repository.ts
@@ -198,6 +198,7 @@ export interface InvoiceCaseRepository {
     errorCode?: string | null;
   }) => Promise<PostingAttemptRecord | null>;
   findPostingAttempt: (id: string) => Promise<PostingAttemptRecord | null>;
+  findLatestPostingAttempt: (caseId: string) => Promise<PostingAttemptRecord | null>;
 }
 
 async function findInvoiceCase(
@@ -786,6 +787,16 @@ export function createInvoiceCaseRepository(database: DatabaseExecutor): Invoice
       return attempt ?? null;
     },
 
+    findLatestPostingAttempt: async (caseId) => {
+      const [attempt] = await database
+        .select()
+        .from(postingAttemptsTable)
+        .where(eq(postingAttemptsTable.invoiceCaseId, caseId))
+        .orderBy(desc(postingAttemptsTable.createdAt))
+        .limit(1);
+      return attempt ?? null;
+    },
+
     createFinanceDecision: async (input) => {
       await database.insert(financeDecisionsTable).values({
         invoiceCaseId: input.caseId,
diff --git a/apps/server/src/services/invoice-case-command.test.ts b/apps/server/src/services/invoice-case-command.test.ts
index e225fd1..8400e7d 100644
--- a/apps/server/src/services/invoice-case-command.test.ts
+++ b/apps/server/src/services/invoice-case-command.test.ts
@@ -27,6 +27,13 @@ function makeDependencies(state: Record<string, unknown>) {
       status: 'pending',
       externalReference: null
     }),
+    findLatestPostingAttempt: vi.fn().mockResolvedValue(null),
+    updatePostingAttempt: vi.fn().mockResolvedValue({
+      id: '44444444-4444-4444-8444-444444444444',
+      status: 'pending',
+      externalReference: null,
+      errorCode: null
+    }),
     applyCorrection: vi
       .fn()
       .mockResolvedValue({ id: caseId, state: 'awaiting_ap_review', version: 3 }),
@@ -155,6 +162,55 @@ describe('Invoice Case command service', () => {
     );
   });
 
+  it('reuses the existing posting attempt when retrying a temporary failure', async () => {
+    const setup = makeDependencies({
+      id: caseId,
+      ownerId: actor.id,
+      state: 'posting_failed',
+      version: 5,
+      currentDraftRevisionId: revisionId,
+      findings: [],
+      apConfirmation: { actorId: actor.id, draftRevisionId: revisionId }
+    });
+    const attempt = {
+      id: '44444444-4444-4444-8444-444444444444',
+      invoiceCaseId: caseId,
+      draftRevisionId: revisionId,
+      idempotencyKey: `invoice-case:${caseId}:revision:${revisionId}`,
+      status: 'failed' as const,
+      externalReference: null,
+      errorCode: 'temporary_failure'
+    };
+    setup.repository.findLatestPostingAttempt.mockResolvedValue(attempt);
+    setup.repository.advanceState.mockResolvedValue({ id: caseId, state: 'posting', version: 6 });
+    const service = createInvoiceCaseCommandService(setup.dependencies as never);
+
+    const result = await service.post({ actor, caseId, expectedVersion: 5 });
+
+    expect(result).toMatchObject({
+      invoiceCase: { id: caseId, state: 'posting', version: 6 },
+      postingAttempt: { status: 'pending', externalReference: null }
+    });
+    expect(setup.repository.createPostingAttempt).not.toHaveBeenCalled();
+    expect(setup.repository.updatePostingAttempt).toHaveBeenCalledWith({
+      id: attempt.id,
+      status: 'pending',
+      externalReference: null,
+      errorCode: null
+    });
+    expect(setup.enqueue).toHaveBeenCalledWith(
+      expect.anything(),
+      expect.objectContaining({
+        jobKey: `invoice-case:${caseId}:posting:${revisionId}`,
+        payload: expect.objectContaining({
+          postingAttemptId: attempt.id,
+          idempotencyKey: attempt.idempotencyKey,
+          expectedVersion: 6
+        })
+      })
+    );
+  });
+
   it('corrects draft with a human revision and invalidates prior confirmation', async () => {
     const setup = makeDependencies({
       id: caseId,
diff --git a/apps/server/src/services/invoice-case-command.ts b/apps/server/src/services/invoice-case-command.ts
index 12d1bb9..dc1551f 100644
--- a/apps/server/src/services/invoice-case-command.ts
+++ b/apps/server/src/services/invoice-case-command.ts
@@ -7,6 +7,7 @@ import {
   createInvoiceCase,
   financeDecision,
   rejectInvoiceCase,
+  retryPosting,
   requestReprocessing,
   resolveFinding as resolveFindingDomain
 } from '@/domain/invoice-cases/invoice-case.js';
@@ -191,11 +192,31 @@ export function createInvoiceCaseCommandService(
         const current = await repository.findCommandState(input.caseId);
         if (!current) throw new InvoiceCaseCommandNotFoundError();
 
+        const retryAttempt =
+          current.state === 'posting_failed'
+            ? await repository.findLatestPostingAttempt(input.caseId)
+            : null;
+        if (current.state === 'posting_failed') {
+          if (
+            !retryAttempt ||
+            retryAttempt.status !== 'failed' ||
+            retryAttempt.errorCode === 'permanent_rejection'
+          ) {
+            throw new InvoiceCaseCommandConflictError('posting_not_retryable');
+          }
+          if (retryAttempt.draftRevisionId !== current.currentDraftRevisionId) {
+            throw new InvoiceCaseCommandConflictError('posting_attempt_stale');
+          }
+        }
+
         const next = runDomain(() =>
-          beginPosting(toDomainState(current), {
-            expectedVersion: input.expectedVersion,
-            actor: input.actor
-          })
+          (current.state === 'posting_failed' ? retryPosting : beginPosting)(
+            toDomainState(current),
+            {
+              expectedVersion: input.expectedVersion,
+              actor: input.actor
+            }
+          )
         );
         const draftRevisionId = next.currentDraftRevisionId!;
         const updated = await repository.advanceState({
@@ -209,13 +230,22 @@ export function createInvoiceCaseCommandService(
         });
         if (!updated) throw new InvoiceCaseCommandConflictError('stale_version');
 
-        const idempotencyKey = `invoice-case:${input.caseId}:revision:${draftRevisionId}`;
-        const postingAttempt = await repository.createPostingAttempt({
-          caseId: input.caseId,
-          draftRevisionId,
-          idempotencyKey,
-          status: 'pending'
-        });
+        const idempotencyKey =
+          retryAttempt?.idempotencyKey ??
+          `invoice-case:${input.caseId}:revision:${draftRevisionId}`;
+        const postingAttempt = retryAttempt
+          ? ((await repository.updatePostingAttempt({
+              id: retryAttempt.id,
+              status: 'pending',
+              externalReference: null,
+              errorCode: null
+            })) ?? retryAttempt)
+          : await repository.createPostingAttempt({
+              caseId: input.caseId,
+              draftRevisionId,
+              idempotencyKey,
+              status: 'pending'
+            });
         await dependencies.enqueue(executor, {
           jobKey: `invoice-case:${input.caseId}:posting:${draftRevisionId}`,
           payload: {
diff --git a/apps/server/src/services/invoice-case-processing.integration.test.ts b/apps/server/src/services/invoice-case-processing.integration.test.ts
index 96904fc..b388a3c 100644
--- a/apps/server/src/services/invoice-case-processing.integration.test.ts
+++ b/apps/server/src/services/invoice-case-processing.integration.test.ts
@@ -1,9 +1,9 @@
 import { randomUUID } from 'node:crypto';
 
-import { eq } from 'drizzle-orm';
+import { eq, inArray, like } from 'drizzle-orm';
 import { drizzle } from 'drizzle-orm/node-postgres';
 import { Pool } from 'pg';
-import { afterAll, beforeAll, describe, expect, it } from 'vitest';
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it } from 'vitest';
 
 import { createDeterministicInvoiceExtractor } from '@/adapters/extraction/deterministic-extractor.js';
 import { enqueueInvoiceCaseProcessing } from '@/jobs/queue.js';
@@ -35,6 +35,50 @@ describe('Invoice Case clean processing', () => {
     database = drizzle({ client: pool });
   });
 
+  const cleanupFixtures = async () => {
+    const matchingRevisions = await database
+      .select({ caseId: invoiceDraftRevisionsTable.invoiceCaseId })
+      .from(invoiceDraftRevisionsTable)
+      .where(eq(invoiceDraftRevisionsTable.invoiceNumber, 'INV-2026-0001'));
+    const matchingCaseIds = matchingRevisions.map((revision) => revision.caseId);
+    if (matchingCaseIds.length > 0) {
+      const matchingCases = await database
+        .select({ sourceDocumentId: invoiceCasesTable.sourceDocumentId })
+        .from(invoiceCasesTable)
+        .where(inArray(invoiceCasesTable.id, matchingCaseIds));
+      await database
+        .delete(invoiceCasesTable)
+        .where(inArray(invoiceCasesTable.id, matchingCaseIds));
+      await database.delete(sourceDocumentsTable).where(
+        inArray(
+          sourceDocumentsTable.id,
+          matchingCases.map((item) => item.sourceDocumentId)
+        )
+      );
+    }
+
+    const users = await database
+      .select({ id: usersTable.id })
+      .from(usersTable)
+      .where(like(usersTable.email, '%@t8.test'));
+    const userIds = users.map((user) => user.id);
+    if (userIds.length === 0) return;
+
+    await database.delete(invoiceCasesTable).where(inArray(invoiceCasesTable.ownerId, userIds));
+    await database
+      .delete(sourceDocumentsTable)
+      .where(inArray(sourceDocumentsTable.uploadedBy, userIds));
+    await database.delete(usersTable).where(inArray(usersTable.id, userIds));
+  };
+
+  beforeEach(async () => {
+    await cleanupFixtures();
+  });
+
+  afterEach(async () => {
+    await cleanupFixtures();
+  });
+
   afterAll(async () => {
     await pool.end();
   });
@@ -121,11 +165,5 @@ describe('Invoice Case clean processing', () => {
       'processing_started',
       'processing_completed'
     ]);
-
-    await database.delete(invoiceCasesTable).where(eq(invoiceCasesTable.id, invoiceCase.id));
-    await database
-      .delete(sourceDocumentsTable)
-      .where(eq(sourceDocumentsTable.id, invoiceCase.sourceDocumentId));
-    await database.delete(usersTable).where(eq(usersTable.id, userId));
   });
 });
diff --git a/e2e/invoice-workflows.spec.ts b/e2e/invoice-workflows.spec.ts
index 425759c..9451fdf 100644
--- a/e2e/invoice-workflows.spec.ts
+++ b/e2e/invoice-workflows.spec.ts
@@ -153,10 +153,12 @@ test.describe('required invoice workflows', () => {
     await submitInvoice(page, 'e2e-duplicate.pdf', true);
   });
 
-  test('temporary posting failure exposes a retry action', async ({ page }) => {
+  test('temporary posting retry keeps one accounting outcome', async ({ page }) => {
     await signIn(page, 'ap.specialist@trestle.demo');
     await page.goto('/cases?status=posting_failed');
     await page.getByRole('link', { name: 'INV-E2E-POSTFAIL' }).click();
-    await expect(page.getByRole('button', { name: 'Retry posting' })).toBeVisible();
+    await page.getByRole('button', { name: 'Retry posting' }).click();
+    await expect(page.getByRole('heading', { name: 'Posted' })).toBeVisible({ timeout: 20_000 });
+    await expect(page.getByText(/ACC-[0-9A-F]{16}/)).toBeVisible();
   });
 });