Why am I seeing a 401 Unauthorized - INVALID_CREDENTIALS error?

28/10/2025  |   Easy MTD VAT

The reason you are seeing a 401 Unauthorized - INVALID_CREDENTIALS error is because the access token that your installation of Easy MTD requires to connect with HMRC is invalid or has expired. To resolve the matter, please perform the following actions:

  1. Select the applicable taxpayer or business in Easy MTD (or any taxpayer or business if you are an agent).
  2. Click the Go button. If your Income Tax or VAT information is successfully shown in Easy MTD, then try the process that caused the error again. If the Income Tax information or VAT information is not shown or the error persists:
  3. Click the applicable Connect link on the Taxpayers page or Businesses page or click the Yes button if you see the Not Connected with HMRC window, then work your way through the process of connecting Easy MTd with HMRC. Now try the process that caused the error again.

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