Registration deadline under HMRC's new tax adviser regime is approaching
As highlighted previously in this article, ACCA members who provide tax advice or interact with HMRC on behalf of clients should be aware that a further registration deadline on 18 August 2026 is approaching. From this date, those with existing agents accounts (but who have not registered for an Agent Services Account) for self-assessment or corporation tax must register under HMRC's new Modernising and Mandating Tax Adviser Registration regime.
Eligible advisers who are new to practice, or who do not already hold an Agent Services Account, Self-Assessment or Corporation Tax agent account, should check whether they are required to register, and submit their application before the deadline.
Registration conditions
To be approved, a business must meet a series of compliance conditions. A central requirement is evidence of supervision under Anti-Money Laundering (AML) regulations.
In addition, the business must not have outstanding tax returns or unpaid tax liabilities (unless covered by an agreed time-to-pay arrangement). It must not be subject to HMRC refusal to deal, anti-avoidance sanctions, stop notices or bans from registration with HMRC.
Relevant unspent convictions for fraud or tax offences, formal insolvency, or similar compliance failures will also prevent approval.
Registration is free, and failure to register where required could result in restrictions on interacting with HMRC on behalf of clients and potential sanctions. Members are encouraged to review the HMRC guidance and registration requirements without delay.
Registration timetable
The new system opened on 18 May 2026. From that date, businesses can begin registering voluntarily, but mandatory registration will be phased:
- 18 May 2026-18 August 2026: agents without existing Self-Assessment or Corporation Tax agent accounts must register from 18 May
- 18 August 2026-18 November 2026: those with existing agent accounts for these taxes must register from 18 August
- 18 November 2026-18 February 2027: agents providing only third-party payroll services, with no other HMRC interaction must register from 18 November
- 31 December 2026-31 March 2027: those who already have an ASA and financial services organisations. A full definition for this group has not been made available publicly yet but more details are expected soon via secondary legislation.
Once the obligation applies, there is a three-month window to submit the application. During this period, agents may continue acting for clients while HMRC processes the registration.
Failure to register when required will prevent agents from dealing with HMRC. Continued interaction without registration may lead to formal stop notices, bans from registration, and financial penalties.
