PHASE 6 · HMRC

From approved records to HMRC.

Test the complete finalisation journey without touching a real tax account.

Demo environment: every HMRC identity, obligation, calculation and reference shown below is fictional.

HMRC SANDBOX CONNECTION

Connect HMRC securely

Production uses HMRC OAuth. POL never asks for or stores a Government Gateway password.

Not connected

STEP 1

Authorise POL

This preview simulates HMRC's OAuth consent journey. In the real sandbox, HMRC redirects the test user to authorise Self Assessment access.

DEVELOPER SAFETY CHECKS

Production gate

✓ OAuth 2.0 authorisation✓ Refresh-token rotation✓ Encrypted tokens at rest✓ HMRC status + obligations adapters✓ Calculation-linked client approval✓ Final declaration adapter○ Fraud-prevention header validation○ HMRC production access

The final two items remain launch blockers. Sandbox capability is not production approval.