The MTD error: VAT number/user ID mismatch (businesses)    
This page is for businesses submitting VAT returns for their own business. If you are an agent submitting returns using your agent services account, please refer to guidance here.


You have been directed to this page because the VAT number set up in VT does match that on HMRC's MTD record for the government gateway user ID entered when you granted authority (or there is no MTD record).

HMRC error code
HMRC's code for this error is CLIENT_OR_AGENT_NOT_AUTHORISED.

Check you are signed up for MTD for VAT
Please see Preparing for MTD for VAT (businesses).

Why this error arises
When any MTD application such as VT sends a request to HMRC for a list of your VAT returns (or attempts to submit a VAT return), it has to supply two pieces of information that identify you. These are the VAT number set up in the application and a 32 character code stored in the application. The code is in turn is derived from the authorisation code issued when you granted authority.

HMRC uses the 32 character code to access the MTD VAT record for the government gateway user ID entered when you granted authority.

This error arises when the two items above do not match.

Causes and resolution
It follows from the above that the error must be caused by one or more of the following:

1. You are not signed up for MTD or the process is not complete
See Preparing for MTD for VAT (businesses). It is not uncommon for users to think they are signed up when they are not. If you are signed up you will have received a confirmation email from HMRC.

You can check if you are signed up for MTD by signing into your business taxes page on HMRC's web site. This will have an MTD section if you are signed up.

If you are not signed up, you will need to do so on HMRC's Sign up for MTD page.

2. The VAT number set up in VT is incorrect
It is a simple matter to check every single digit. It should be 9 digits long.

3. The wrong government gateway user ID was used when granting authority
VT has no way of knowing what user ID was used to grant authority or of accessing the name of the user. Hence the best thing to do is to simply grant authority again and be very careful that the correct user ID is entered into HMRC's web page.

When re-granting authority, make sure the checkbox labelled I'm using my agent services account... is unticked.

Also ensure you are using the government gateway credentials used to sign up for MTD and not for any other online services.

4. There is a fault with your MTD record on HMRC's computers. This is possible but unlikely. Please contact the HMRC online services helpdesk

VT would like to assure you that this error does not arise from a software fault in VT.

VT is not able to provide support on the use of HMRC's web site. If necessary, please contact the HMRC online services helpdesk.

VT Software>Topics>MTD>The MTD error>Businesses