HMRC has opened the second phase of mandatory tax adviser registration, with eligible advisers required to register by 18 November 2026. The new online registration requirement rolled out earlier this week for advisers who hold Self Assessment or Corporation Tax accounts but do not yet have an agent services account (ASA).
Who needs to register in phase two
Advisers in this second window must check whether they need to register and submit their application as soon as possible, HMRC said. The registration process is free and conducted entirely online. Step-by-step guidance and an interactive checker tool are available on GOV.UK to help advisers understand their obligations and the application process.
Advisers who solely provide professional payroll services are not required to register before 18 November. Financial Services organisations have until 31 December 2026 to complete their registration.
Purpose of the mandatory registration
HMRC hopes the mandatory tax adviser registration requirements will protect customers and raise standards in tax advice. Eligible tax advisers must meet HMRC’s registration conditions to apply for an ASA. Robert Jones, HMRC’s Director of Intermediaries, said: "Together, these measures will reinforce trust and transparency across the tax advice market, supporting high standards and helping taxpayers access advice with greater confidence."
Jones added: "Now that the second registration phase is open, advisers in the next group should check the guidance on GOV.UK and make sure they register by 18 November 2026."
Consequences of missing the deadline
Advisers who missed the first registration window or who are new entrants to the tax advice market should register as soon as possible. Those who submit an application and receive a registration number can continue to engage with HMRC while their registration is being processed, and access to HMRC’s online services will not be affected in the short term.
However, HMRC may limit an adviser’s ability to act on behalf of clients if they fail to register when required. Advisers who continue to operate without completing the registration requirement could also face enforcement action, including financial penalties. Registering on time will help advisers continue supporting their clients without disruption and maintain the trust that individuals and businesses place in professional tax services.
