We've put together a list below of common errors that can occur and their solutions, however we recommend you first check the HMRC service status to ensure the Making Tax Digital (MTD) service is currently available.

An error has occurred when communicating with the submission service

Blank screen when submitting on HMRC portal 

A blank sign in page appears when attempting to submit a VAT Return for MTD. We fixed this issue in Sage 50 Accounts v26. Download and install Sage 50 Accounts v26 or above now >

Error 400

If you receive error 400, please try again later.

Error 403 - The client and / or agent is not authorised

This can occur for several reasons when you log in to the HMRC website as part of your MTD submission. To resolve this, you need to check certain areas. Full details in our MTD errors - An error has occurred when communicating with the submission service. Please try again later guide.

Internal server errors 

In many cases, despite this message, HMRC may have received your submission.

You can also get these messages for the following reasons:

• Incorrect VAT registration number
• You're not registered for MTD with HMRC

There are some things that you can check on HMRC's website to resolve this. You can follow our Error: 'Internal server Error' on MTD VAT submission guide to do this.

Obligation period is missing

When submitting your VAT Return under Making Tax Digital (MTD) the obligation period drop-down is blank or doesn't show the correct obligation period. To resolve this, you need to check your computer's regional settings, your VAT number is correct within Sage 50 Accounts and all computers that access your Sage 50 Accounts data are on the latest version. Use our Making Tax Digital for VAT - Correct obligation period is missing when submitting VAT Return guide to fix this.

The organisations/VAT API is currently unavailable

This can occur if HMRC are experiencing MTD service issues or the service is unavailable. If you receive this message we recommend you try submitting again later. You can check the current service status on the GOV.UK website.

The remote endpoint has indicated no data can be found

This can occur if you:

Attempt to submit your VAT Return for a VAT period that has not yet ended.

• Try to submit for a period HMRC is not expecting a submission for.
• To resolve this, in the Submit your period drop-down, click the correct VAT period.

If you choose the correct period and the message still appears, you must contact HMRC and ask them to open the VAT period you're attempting to submit for.

TAX_PERIOD_NOT_ENDED

This occurs if you attempt to submit your VAT Return for a VAT period that has not yet ended. To resolve this, follow this steps in our 'Error code: TAX_PERIOD_NOT_ENDED'guide.

The VRN specified [VRN] was not found

This occurs if you don't activate MTD within Sage 50 Accounts before you submit your first MTD VAT Return. This error can also occur if you're using the MTD module but try to submit through the old Government Gateway using the Sage 50 Accounts VAT Return. Follow our Making Tax Digital - 'VRN specified was not found' or submitted VAT Return without first activating MTD in software guide to fix this.

Unable to send request. Cannot open Internet connection. Unknown 12007

This occurs if you've signed up with HMRC for MTD for VAT, but you're trying to submit your VAT Return through software that's not MTD compliant. To resolve this, follow the steps in our Error: 'Unable to send request. Cannot open Internet connection. Unknown 12007' on MTD VAT submissions guide.

User has already submitted a VAT Return for the given period

This message appears if you try to submit a VAT Return more than once for the same obligation period. 

If you submit your VAT Return and then make an adjustment, you can submit this adjustment in the next obligation period provided its value is no more than £10,000.

If you need to make an adjustment of more than £10,000 you must contact HMRC.

Your VAT Registration Number is invalid. Please check this in Settings > Company Preferences > VAT tab

There is an issue with your VAT number in the software. To resolve this, follow the steps in our Error: 'Your VAT Registration Number is invalid. Please check this in Settings, Company Preferences, VAT tab' on MTD VAT submission guide.

NOTE: If your MTD error isn't listed here, please enter the exact error message in the Search for answers bar at the top of this page.

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