Connecting to HMRC

Before Aligned can retrieve your tax obligations or submit returns on your behalf, you need to connect your HMRC account. This is a one-time setup that takes about 2 minutes.

The 3-step connection flow

Step 1: Enter your details

Visit the Get Started with HMRC page at /app/hmrc/get-started.

Individuals: Enter your National Insurance number (NINO) in the format AA 12 34 56 A
Agents: Enter your Agent Reference Number (ARN)

Click Connect to HMRC when ready.

You will be redirected to the HMRC Government Gateway sign-in page. Sign in with your Government Gateway user ID and password, then grant Aligned permission to access your MTD data.

Your Government Gateway password is never stored by Aligned. The connection uses OAuth 2.0 - only a secure authorisation token is exchanged.

Step 3: Account setup

After granting permission, you will see a live progress screen showing each step as it completes:

Checking your MTD enrolment status
Fetching your business details from HMRC
Loading your upcoming tax obligations

Once complete, you are automatically redirected to your dashboard.

Reconnecting

If your authorisation expires (typically after 18 months), you will see a Reconnect to HMRC prompt. The process is the same 3 steps, but your NINO or ARN will be pre-filled from your previous connection.

Reconnecting does not affect your existing data or submission history.

What if MTD is not authorised?

If HMRC reports that your account is not enrolled for Making Tax Digital, you will see a warning during step 2 of the connection. You can still continue to your dashboard, but you will need to enrol for MTD with HMRC before submitting returns.

Troubleshooting

Invalid NINO format - Check the format is two letters, six digits, one letter (e.g. QQ 12 34 56 A). Prefixes BG, GB, NK, KN, TN, NT, and ZZ are not valid.
Connection failed - Try again. If the problem persists, check your internet connection and try a different browser.
Government Gateway sign-in issues - Contact HMRC for help with your Government Gateway account.

Security

OAuth 2.0 with PKCE protects the authorisation flow
Your NINO is encrypted at rest using PII-specific encryption
Your Government Gateway password is never seen or stored by Aligned
You can disconnect at any time from Settings