We remind readers that Mandatory Tax Adviser Registration commenced last month from 18 May 2026. HMRC has now published updated guidance to help overseas advisers assess their obligations under this legislation which will be of particular interest to our members in Ireland and overseas who may also be required to register for an agent services account. For both overseas and UK based advisers, the first three-month MTAR window may have commenced from 18 May 2026, unless a later start date applies. HMRC has also published a new MTAR manual.
After MTAR launched last month, HMRC began hosting weekly stakeholder drop-in sessions for trusted stakeholders, including Chartered Accountants Ireland. The purpose of these sessions is to establish a regular forum to:
- share feedback on the new service and user experience,
- highlight any early operational or technical issues, and
- raise questions or concerns as they arise.
HMRC expects these sessions to support early identification and resolution of issues, and to ensure stakeholder insight is captured as the service embeds. These sessions are attended by HMRC representatives from the policy, project delivery, and IT teams responsible for delivering MTAR. Chartered Accountants Ireland therefore encourages members to share their feedback on MTAR with us so that this can then be discussed with HMRC at these sessions.
In addition to HMRC’s guidance pages which we have previously shared, HMRC has published a range of additional MTAR resources. An interactive guidance tool is also available in addition to a useful factsheet covering common questions, including:
- The transition period,
- The scope of the registration requirement, and
- Those within businesses (known as relevant individuals) that need to meet the registration conditions.
As a reminder, HMRC is introducing the requirement to register in stages. The current timetable to register is as follows:
| 18 May to 18 August 2026 | New tax advisers, including overseas advisers who do not currently have an Agent Services Account (ASA), or online Self-Assessment or Corporation Tax account. |
| 18 August to 18 November 2026 | Tax advisers who have an online Self-Assessment or Corporation Tax account, but no ASA. |
| 18 November 2026 to 18 February 2027 | Tax advisers who solely provide payroll services and who do not have an ASA. |
| 31 December 2026 to 31 March 2027 | Financial services organisations with no ASA (a full definition for this group will be set out in secondary legislation). |
Tax adviser businesses have three months from the start of their registration window to apply. During this period, and whilst their application is being considered, they can continue to interact with HMRC on behalf of their clients.
Those with an existing ASA do not have to register again with HMRC. HMRC will contact these businesses between January and March 2027 so that checks can be conducted against the new registration requirements.
To assist members with meeting their obligations under this legislation, the Institute’s MTAR hub contains a suite of resources to help you determine if you are in scope, when you need to register, and what actions you need to take. Further resources on the various sanctions available to HMRC under this legislation will be added to the hub in the coming months.
LOADING...