UK – HMRC: Mandates Tax Advisers to Register Online for Agent Services Account 

HMRC is strengthening its monitoring position for tax advisors. On May 18, 2026, it will launch an online registration portal specifically dedicated to agent service accounts. The new system will replace the current one. All tax advisers who aren’t registered but should be, or future ones, should follow the new registration procedures. 

HMRC advises all tax agents who are legally required to register to do so through the new system when it becomes operational. The online registration procedure will be gradual. Registered agents who haven’t already migrated don’t have an obligation to migrate to the new system. 

Tax Advisers 

In a broad sense, HMRC sees persons who interact with it about someone else’s tax affairs and get paid for it as tax advisers. When this is the case, these persons should register themselves with HMRC as tax advisers. 

The communication with HMRC includes: 

• phone, post, or email 
• messages through the GOV.UK website or HMRC app
• sending returns, claims, or other documents

Persons who handle someone else’s tax affairs before HMRC should register as tax advisers, even though they don’t “see” themselves as “proper” tax advisors. Some of the conditions that trigger your obligation to register as a tax advisor(not an exhaustive list of conditions):

• Even though you don’t describe your work as being a tax advisor, you may be liable to register 
• You work as a registered sole trader
• Helping people with their tax affairs is not your main business function
• You only interact with HMRC on behalf of one client
• Your business is based outside the UK

You also will not need to register if you only interact with HMRC:

• on customs or import VAT
• as a VAT representative (appointed to handle VAT matters for a business)
• to represent a client in appeals to a court or tribunal

Registration Deadline

Responsible tax advisers should register for the agent services account on or after May 18, 2026, unless another deadline applies. There is a 3-month registration deadline from the date of your registration.

Late registration 

The tax advisers who don’t register for an agent services account will not be able to interact with HMRC on behalf of their clients. 

If cases of negligence occur, we may: 

• Issue a formal notice asking you to stop
• temporarily or permanently ban you from being able to register