Personal Tax/VAT/MTD – Client/Agent is not recognised OR National insurance number is incorrect

personal-tax-client-agent-is-not-recognised-or-national-insurance-number-is-incorrect

Personal Tax/VAT/MTD – Client/Agent is not recognised OR National insurance number is incorrect

4th February 2026

The “client or agent not authorised” error in IRIS Personal Tax for MTD or HMRC Data retrieval or the VAT filer, this indicates that HMRC does not recognise your current credentials as authorized to act for that client. This can be caused by expired, incorrect, or missing digital authorisation or incorrect National Insurance number entry (It requires a “digital handshake” between IRIS and HMRC).

IF ALL clients are affected – Run the steps on this KB (especially resetting your HMRC LOGIN)

IF a specific client is affected – If the client is new or old, run the steps on this KB and check step 7 and its example.

NOTE: This may happen even when its worked fine before eg Randomly you get this ‘Agent/NI Incorrect’ error when everything is correct – you may need to reset your ASA/agent login several more times for it to pick up the periods/client data and if that doesn’t work, to contact HMRC support (see step 7).

Personal Tax: ‘MTD’ and ‘HMRC data retrieval’ are not the same and are different processes. MTD is specifically for ‘Quarter period submissions’. ‘HMRC data retrieval’ is for pulling in specific data like employment details and values into a PT client records.

1.Update to the latest IRIS version – help and about. This is because PT MTD and VAT need to be on the latest versions to work. For VAT affected clients just see above.

For VAT Filer only:

1. Go to Client and View – find the ‘VAT reg code’- then delete it, save, go back in and type the vat code back in manually and save
2. Go to client and view and ‘Accountant’ and check the correct option is ticked (eg normally its AGENT). If its alternative – ask your team to check if this is correct etc.
3. Reset your ASA login – go to Authorised agents, find your VAT row, reset it and yes, exit the screen. Select the ‘Refresh client’ button and login with your ASA login etc. Now try and work on the VAT client again (The resetting steps may need to be run several times and there can be a 24/48hrs delay for periods to show).

1. Client and View – Accountant – check its set to’ AGENT’. If its set to Branch and Alternative – ask your team why and if the answer is unclear/no one answers then keep a note of this change and manually change to AGENT, save and try the client again. Branch is when you have different offices all over the UK. Alternative is when someone is trying to submit not via your main office AGENT account but with a different login, so if its set to this then always check.

2. Check the clients NI and UTR Numbers If you get the warning for ALL your clients then its less likely a NI or UTR number issue

• Ensure the National Insurance and UTR number is entered correctly in the Client > View > Tax tab and note them down
• Verify that the NI number meets HMRC formatting rules (2 letters, 6 digits, 1 letter) and the UTR meets the HMRC rules.
• Delete the national insurance number and UTR code, save, ok to close
• Change to a random client and load back to the affected client (to refresh the screens)
• Go back and manually enter in the NINO and UTR and save (Do not copy and paste it back in)
• Now try again – if same warning proceed to resetting your ASA account on step 3)
• This is also linked to ‘Matching resource not found’ warning when submitting MTD quarters so follow the steps above on the NINO code.

3. Reset Agent Credentials for MTD or HMRC Data retrieval If you are receiving this error while trying to retrieve MTD quarter periods OR HMRC pre-population data:

• Go to Setup | Auth agents.
• We recommend you try one of the reset steps below (MTD or HMRC data retrieval) and not do both at the same time so you can see if that corrects the issue, if not then do the next one.
• Select the row for MTD row called ‘Self Assessment’ (this is the name for MTD usage) and then choose the reset credentials. Click Yes and Ok to close
• Select the row for HMRC data retrieval row called ‘Pre-Population’ data and then choose the reset credentials. Click Yes and Ok to close
• DO NOT CLICK ‘Agent services account sign up’ as this is only for users who do not have a ASA login or a Agent login.
• For HMRC Data retrieval, click Retrieve HMRC Data button to log in and re-authorise using your ‘Agent’ login and may ask security questions
• For MTD, go to ‘retrieve the quarter periods’ and login and re-authorise using your ‘ASA’ login and may ask security questions
• Now retrieve data or periods
• There is a random issue where you still get this ‘Incorrect’ error when everything is correct – you may need to reset your ASA/agent login TWO more times for it to pick up the periods/client data.

4. For MTD only, check you have setup your client correctly. This is a HMRC requirement on their website: You need to move your Personal Tax clients to your ASA account and then sign them up for MTD on the HMRC site, if you need advise on this then contact HMRC Support to ask they check its been setup correctly (as IRIS can only advise with you if this was done). If this is incorrectly done or incomplete then the MTD will not work for the affected clients.

5. Remember to REFRESH the client. By either changing client and reloading the affected client again and try the steps AND/OR close IRIS and restart it.

6. There can be a TIME DELAY when you reset your ASA login etc – when you reset and login again but nothing changes in VAT/PT/MTD – there can be a delay of 24/48hrs before HMRC picks up your recent reset which is why nothing changes. This mostly affects VAT. After 24/48hrs and you still have the issue, can you reset your login ONE MORE TIME and try again.

7. NOTE: The NI/Agent not authorised warning may appear for ‘specific clients’ and not all clients, if you have done the steps 1,2,3,4,5,6 above and still having this issue then you have done everything you can from the IRIS area. We now recommend you contact HMRC support and speak to a senior as there could be a issue from their side. Ask they check everything from their side etc especially your HMRC login account, any fellow users linked to this ASA login and the clients linked to MTD and if anything can be fixed/reset/refreshed etc (you may need to provide the clients details). As these NI/Agent authorised warning appear randomly, there could be data issues between IRIS and HMRC which causes these warnings.

Example of a specific Client: A PT/MTD user called HMRC support and they found out their specific client getting the client/auth/NINO warning still had their prior accountant agents details linked to their online account. HMRC gave instructions to this one client to go to ‘manage my agents’ option and then remove the previous agent and then setup up the correct accountants agent details. This could be a method to refresh the data if you have clients having a issue, remove the current agent and set it back up again and we recommend you contact HMRC on how to do this.