Deadlines for HMRC tax adviser register from 18 May

18 May 2026

With a few days to go before mandatory tax adviser register goes live on 18 May, HMRC issues timetable for registration with dates for staggered introduction

Online registration will be rolled out in stages between 18 May 2026 and 31 March 2027.

HMRC said the system ‘will be introduced gradually, with different groups invited to register at different stages’.

Deadlines:

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 agent services account.

18 November 2026 to 18 February 2027
Advisers who solely provide payroll services.