Tax Adviser Registration Starts

A tax adviser is a wide definition and is someone who interacts with HMRC on behalf of someone else and is paid for it, for example, a client for the provision of services. This applies to any tax administered and collected by HMRC, for example, Income Tax, Corporation Tax, VAT etc.

Interaction includes the following: 

• Providing advice;
• Acting as an agent on behalf of the other person (in relation to a tax);
• Assisting with a document HMRC can rely on to determine a tax position;
• Contacting HMRC by any means;
• Filing returns, claims, etc or other documents; and / or
• Any other communication / interaction 

Mandatory registration is staged as follows: 

18 May to 18 August 2026 

• New tax advisers; or
• Advisers interacting with HMRC without an Agent services Account (ASA), Self-Assessment or Corporation Tax account

18 August to 18 November 2026

• Advisers with a Self-Assessment or Corporation Tax account, but without an ASA

18 November 2026 to 18 February 2027

• Advisers who solely provide payroll services

ICB points to the following help and resources which we advise members to review:

• Does your business provide tax services? (online checker tool)
• Check if and when you need to register as a tax adviser with HMRC;
• What happens if you interact with HMRC when you are unregistered or suspended as a tax adviser;
• Mandatory tax adviser registration — communications resources;
• Sanctionable conduct by tax advisers: who is a tax adviser; and
• How HMRC deals with tax adviser sanctionable conduct

For Bookkeepers

We understand and support HMRC’s need to be able to verify the identity of people who interact with them on someone else’s behalf. 

For members, we recommend you give this priority, as the consequences of non-registration are serious, ranging from compliance notices to suspension and, ultimately, large penalties for sanctionable conduct.