R&D tax relief changes in 2026: Mandatory registration of tax advisers

Brought in, in response to 2024 consultation about how to raise standards in the UK tax advice market, mandatory registration for tax advisers is currently expected to come into force in Spring 2026. This will affect any tax adviser who interacts with HMRC on behalf of their client, meaning that most, if not all, R&D tax relief advisers will be required to register with HMRC.

Who has to register?

Any tax adviser who interacts with HMRC on behalf of their clients must register. According to the draft legislation, a tax adviser is anyone who:

Advises another person in relation to tax;

Acts as an agent on behalf of another person in relation to tax, and/or;

Provides assistance with documentation that is likely to be relied upon by HMRC to determine the other person’s tax position.

While there are some exemptions to this, they wouldn’t apply to advisers working in R&D tax relief – in fact, it’s safest to assume that if you do any work related to R&D tax relief, HMRC would consider you to be a tax adviser!

What counts as interacting with HMRC?

The legislation is pretty comprehensive in this regard – any form of contact with HMRC, from phone calls or website messages through to filing any kind of document with them would count as interacting with HMRC.

What are the eligibility criteria?

The eligibility criteria for registering as a tax adviser are extensive, but any ethical adviser currently working in R&D tax relief should meet them without having to make any major changes. The tax adviser must:

Meet standards expected of tax advisers (to be published by HMRC)

Be registered for AML supervision

Have no outstanding tax returns or tax due;

Not be subject to sanctions or a decision by HMRC not to deal with them;

Not be subject to suspension or a suspension order;

Not be subject to prohibition or a prohibition order;

Not be disqualified as a director, under any jurisdiction;

Not be insolvent;

Not have any unspent convictions for certain offences.

What effect will this have on the R&D tax advice sector?

Fundamentally, this will prevent R&D advisers from submitting R&D claims to HMRC unless they are registered, which should mean that the sector is better monitored, and unethical advisers will find it harder to operate in the ways they have in the past.

We’re hopeful that holding advisers to a set of standards will improve behaviour in the sector, reducing error and fraud and going some way towards restoring faith in the R&D tax relief regimes on both sides.

What can advisers do to prepare?

The legislation related to this is still only in draft form, so some changes may still be made to the rules or the effective date of mandatory registration, meaning that for now, advisers will just have to wait. However, it’s definitely worth advisers taking the time now to make sure that they are working to PCRT guidelines, AML registrations are up to date and all tax affairs of the advisory firm are up to date in anticipation of applying for registration in the spring.

Here is the policy paper

Stay informed as HMRC finalises the rules

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