MTD Quarterly Filer - Known Errors

From initial testing we have established the following issues when setting up/submitting quarterly updates:

HMRC error '403 Client or Agent Not Authorised' when trying to link the business

This is usually because the client is not registered for MTD, the agent does not have an Agent Services Account or the client has authorised the agent to act on their behalf. Individuals should check their government gateway accounts to ensure they are registered for MTD (or start the registration process). Agents should ensure they are using the correct log in credetials, which is the government gateway account linked to their Agent Services Account credentials (and not the legacy online services Government Gateway credentials) and ensure the client can be seen as authorised and signed up for MTD on their Agent Services Account.

Quarterly Statuses - not all periods retrieved from HMRC

After amending to 'Calendar' option in Business Information, when clicking 'Refresh HMRC statuses', potentially not all obligation periods will be retrieved. This is because of a delay in HMRC systems changing the obligation period dates. Clicking 'Refresh HMRC statuses' again later should retrieve all four periods.

HMRC error 'Matching Resource Not Found' when submitting an update period

This suggests that HMRC do not recognise the business ID. We suggest calling HMRC on the pilot customer helpline that would have been provided when registering the client for the pilot scheme. This message will also appear if the 2026/27 tax year has been signed up for but a submission has been tried for 2025/26. HMRC will be able to correct the year in their system from 15 December 2025, after a system update.

HMRC error 'Rule Start Date Not Aligned with reporting type' when submitting an update period

If an election to submit 'Calendar' quarters was made but then changed to 'Standard' (by HMRC changing the business record on their system), firstly ensure that 'Refresh HMRC statuses' (found in Quarterly Statuses) has been clicked so that the obligation periods reflect the correct start and end dates.

If the first obligation period was submitted with a start date of 1 April (to overcome the error) then subsequent obligation periods should also be submitted with a start date of 1 April.

If this has been done and the error still occurs, it will probably be related to an HMRC's system not recognising the change in reporting type. We suggest calling HMRC on the pilot customer helpline that would have been provided when registering the client for the pilot scheme.

Response error 'Error state set but empty response or no errors in response' when fetching obligations

This error can occur when  a period has been created in Quarterly Filer which does not match the MTD period signed up for with HMRC. Unlinking the business, deleting the period and recreating the correct period, then re-linking the business in Quarterly Filer will usually resolve this issue.

Connection error when trying to authorise TaxCalc to connect to HMRC

This is caused by the system environment blocking access to HMRC server. We recommend contacting your IT support/hosted team and ask them to try excluding the sites in the below knowledgebase article from the proxy server (if not already done):

Excluding sites from Proxy Server checking

And to also try excluding the below site from the proxy server:

api.service.hmrc.gov.uk (used by MTD APIs)

Try authorising to HMRC again in TaxCalc

HMRC error 'Unable to add item as id has not been set' when trying to submit a quarterly period to HMRC

This appears to be due to a connection interruption with HMRC. If you do receive this message, please contact TaxCalc Support quoting the case reference PROD-16034 so we can keep a track of these instances to investigate further.

Error 401 'No available token'  when submitting the quarter

If you are getting the above error please follow the instructions below to resolve this:

• Launch Admin Centre
• Click on Applications
• Click on Customise MTD Quarterly Filer.
• Select HMRC API Token Management.
• Please select and click on Delete Token with the MTD tokens in this section.
• Click on Continue or Finish and then click on Finish and Save.
• After this has been completed, please do the following:
  1. Open the client in MTD Quarterly Filer and click on Link Business. This will take you to the HMRC screens where you will need to log in using the government gateway credentials linked to the Agent Services Account.

If the error message persists, please ensure you are using your correct agent services account. You may need to contact the pilot helpline if you are unable to fetch the token from HMRC.

Duplicate businesses appearing in Quarterly Filer

If you have duplicate businesses appearing in MTD Quarterly Filer, then you will need to delete the business from the client record within Practice Manager.  If you only use MTD and the first quarter has not been submitted then please delete this period, then delete the business from the client record.

However further steps will have to be taken if you receive and error stating : 'Unable to delete business'.

This error occurs if you have VAT Periods, Accounting periods or MTD Quarterly Filer periods associated to that business record. The first step is to ensure which one of the businesses is the 'original', if VAT or accounts periods exist for it. 

• In PM > client record > business - check ‘anticipated turnover’ - if this has an entry greater than zero, this is a sure indication that a tax return is linked with the business
• In the latest tax return, check the business name in the self employment - often the business record created from HMRC linking will be different, so the one used in the tax return will be the original
  1. If both businesses have the same name, rename the business that does not have anticipated turnover by adding 'x' or similar ( this makes it clearer in MTD QF)

Once the ‘original’ business has been identified, in MTD QF

• In Business information, click ‘Refresh’ so that the duplicate (renamed) business is clear
• Business information - expand on the left hand panel and highlight the duplicate business and click on ‘Unlink’
• Business Information - click on Link businesses
  1. then select ‘use existing business’ and select the correct original business
• Back to PM > Client record > select the duplicate business and ‘delete’

If the business still cannot be deleted in the client record, please enter a cessation date within the duplicate business so this does not appear in MTD Quarterly Filer.