Making Tax Digital error - "An error has occurred when communicating with the submission service. Please try again later." / "Error 403 - The client and/or agent isn’t authorised."

How to check and resolve this error, which can appear when you submit a VAT Return from Sage 50 Accounts to HMRC.

When you submit your VAT Return under Making Tax Digital (MTD), one of the following messages can appear:

'An error has occurred when communicating with the submission service. Please try again later.'

When you click Details, the following appears:

'Error 403 - The client and/or agent isn’t authorised.'

HMRC systems can return this error for several reasons, depending on whether you're making your own MTD submission or if you're an agent submitting on behalf of a client.

To correct the error, follow the steps below, but if the issue persists, contact HMRC for further clarification.

 NOTE: This error occurs when you select the wrong period for submission.

Try logging in again

To try to submit again with the correct Government Gateway ID:

 

1. On the error window, click OK, then click Cancel.
2. Click Submit Online and retry the submission, checking your Government Gateway login details are correct.

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Things to check for customers and agents

• Make sure you, or if applicable your client, have registered for MTD and actioned the emails received during the registration process.
• Processing your registration might take up to 72 hours, so make sure enough time has passed
• Check that you have enabled MTD in your software. Click Settings, then click Company Preferences and click VAT, then ensure Enable Making Tax Digital is ticked, then click OK
• Make sure you, or your client, have entered the correct VAT number with no spaces in Sage 50 Accounts. To check this, click Settings, then click Company Preferences. Once checked, click OK
• When completing the MTD VAT submission window, ensure Used stored credentials hasn’t been ticked
• Is my software compliant with Making Tax Digital?
• This error can appear at busy times, especially near MTD deadlines, so if possible, try again later

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Other checks to make if you’re submitting for your own company

• When making your submission, ensure that you’ve entered the correct credentials. Refer back to any emails from HMRC to confirm
• If you have more than one Government Gateway ID, retry your submission with the alternative credentials
• Check that your computer's regional settings is set to English (United Kingdom). To check this, hold down the Windows key  and press R, then type intl.cpl and click OK

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Other checks to make if you're an agent acting on behalf of a client

If you're an accountant using Sage 50 Accounts Client Manager, follow these steps first:

1. Click Settings, then click MTD for VAT Settings...
2. Click Delete Stored credentials.
3. Submit again and when completing the MTD VAT submission window, ensure Used stored credentials isn’t ticked.

If the problem persists:

• Check that you're entering the correct credentials and attempt the submission again. Use your Agent Services Account credentials
• Set up an agent services account and sign-up clients for Making Tax Digital
• When making your submission, ensure that you’ve entered the correct credentials. Refer back to any emails from HMRC to confirm
• If you have more than one Government Gateway ID, retry your submission with the alternative credentials
• Ensure your computer's regional settings are set to English (United Kingdom). To check this, hold down the Windows key  and press R, then type intl.cpl and click OK

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Next steps

If you've completed those steps contact HMRC to find out why they aren’t accepting your MTD submission.