Mandatory Tax Adviser Registration is here

To mark the official commencement date of Mandatory Tax Adviser Registration (MTAR) which starts from today, 18 May 2026, we have now launched our MTAR hub which contains a suite of resources to help members identify if they are in scope, when they need to register, and what actions they need to take. Further resources on the various sanctions available to HMRC on this legislation will be added to the hub in the coming months. In the meantime, we strongly recommend that any of our members based in the UK who regularly interact with HMRC on behalf of their clients check their obligations under MTAR and determine their registration timeline. Overseas advisers who are in scope will also need to register with HMRC at a date still to be determined.

Last week HMRC published additional guidance and resources on MTAR as follows:

• Mandatory tax adviser registration — communications resources, and
• Check if and when you need to register as a tax adviser with HMRC.

HMRC has also published updated guidance for agents on how to protect your sign in details and reduce the risk of fraud when using HMRC online services. This has been published ahead of multi-factor authentication being switched on for agents in the coming months, the timetable for which is expected imminently from HMRC.