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Error: Cannot connect to HMRC

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Summary

How to fix the error preventing you from connecting HMRC to Sage Accounting. This error occurs when setting up Making Tax Digital (MTD) for Income Tax.

Description

The most common reason this error occurs is when you're not signed up for MTD:

Sign up for MTD for Income Tax with HMRC at gov.uk/guidance/sign-up-for-making-tax-digital-for-income-tax.

  1. Within the onboarding process, check that your National Insurance number is correct.
  2. Select Edit it on the Find your business screen.
  3. Use the same number you used during HMRC sign-up.

Resolution

If the National Insurance number is correct

If Sage can’t find your income source during connection, the issue is usually with your HMRC account rather than Sole Trader. Work through the checks below:

▼ Log into your HMRC Personal Tax Account

Go to your HMRC Personal Tax Account and look for your income sources.

If no active source appears here, Sole Trader can't connect because HMRC doesn't recognise the record.

▼ Confirm your income source registration with HMRC

If you've recently started self-employment or begun receiving UK property income, this can take up to 10 working days.

It's possible that HMRC is currently processing your registration.

▼ Confirm you’re using the right Government Gateway account

You could have more than one Government Gateway login. Check you're signed in with the account linked to your Unique Taxpayer Reference (UTR) and Self Assessment record.

A mismatch between accounts will prevent the connection from completing.

▼ Confirm your income type is eligible

MTD for Income Tax covers self-employment income and UK property income held in your own name.

Income received through a limited company, partnership, or as an employee doesn't connect through this route.

▼ Confirm the HMRC authorisation is complete in full

When connecting Sage to HMRC, you must complete the full HMRC authorisation journey and receive a confirmation from HMRC at the end.

If you've navigated away before receiving that can cause the authorisation to fail. Authorisation also expires over time. Previously connected and now see an error? Repeat the authorisation journey from the start.

▼ Confirm your income source is correctly set up in Self Assessment

HMRC needs to recognise your income source in the correct tax context for the connection to work.

Check the income is declared on a prior Self Assessment return under the correct category. Confirm it’s held personally, not through another legal structure.

▼ Check for multiple or ceased income sources

Stopped and restarted a business or registered multiple income sources? Old records may exist alongside your active one.

This can cause the wrong record to surface during the connection, log in to your HMRC account and confirm which sources show as active.

 

If HMRC still doesn’t show an active income source after these checks, you need to contact them.

HMRC Self Assessment general enquiries: 0300 200 3310

Monday to Friday, 8am to 6pm

After HMRC confirm the source is active and visible, return to Sage and try connecting again. Contact our support team to investigate further if the issue persists.