Mandatory Registration with HMRC for Tax Advisers
From May 2026, HMRC will begin rolling out a new online registration system for agent services accounts (ASA), marking a significant change in how tax advisers and other paid intermediaries engage with HMRC. This reform is part of HMRC’s broader strategy to strengthen oversight of the tax advice market, improve transparency, and ensure that anyone acting on behalf of taxpayers meets consistent standards. For firms and individuals who interact with HMRC about clients’ tax affairs, understanding whether and when registration is required will be essential to maintaining uninterrupted service to clients.
Under the new rules, anyone who interacts with HMRC on another person’s tax affairs and receives payment for doing so will generally be regarded as a tax adviser and will need an agent services account. Interaction is defined widely and includes communicating with HMRC by phone, post, email, or through digital channels such as GOV.UK or the HMRC app, as well as submitting returns, claims, or other documents. Crucially, it is the legal entity that deals with HMRC that must register. Individual employees within a firm do not need separate registration, although HMRC will carry out suitability checks on certain people connected with the business.
The requirement applies regardless of how a business describes its services or how small its involvement may be. Registration will still be necessary even where tax advice is not the main business activity, where a business acts for only a single client, or where the adviser is based overseas. Sole traders are also within scope. HMRC’s approach reflects its view that any paid intermediary influencing or handling tax compliance should be visible within its regulatory framework, regardless of professional labels or scale of activity.
There are, however, important exclusions. Employers and in-house tax teams managing payroll or tax matters solely for their own organisation or corporate group do not need to register. Nor is registration required where tax help is provided free of charge, such as by charities or informal assistance to friends and family. Certain professionals who interact with HMRC because legislation requires them to do so, including insolvency practitioners or some pension and investment providers, are also outside the regime. Software developers that enable filing but do not themselves communicate with HMRC on behalf of clients are similarly excluded.
Specific types of representation are also carved out. Businesses that interact with HMRC only in relation to customs or import VAT matters, act solely as VAT representatives, or serve as Northern Ireland or UK representatives for particular overseas tax obligations do not fall within the new registration requirement. Likewise, representing taxpayers in court or tribunal appeals, or responding to statutory information notices, does not in itself create a need to register as a tax adviser.
The timing of the obligation will be phased. From 18 May 2026, most affected advisers must register unless they fall into categories given later start dates. Those who already hold Self Assessment or Corporation Tax agent accounts will have until 18 August 2026 to register under the new ASA system. Businesses that only provide third-party payroll services and have no other HMRC interaction will have until 18 November 2026. Although the requirement dates differ, the online registration service will open on 18 May 2026, allowing organisations to register early if they wish.
Once the relevant start date applies, advisers will have a three-month window to complete registration. During this period, and while HMRC considers the application, they may continue interacting with HMRC on behalf of clients. Before applying, businesses should review HMRC’s conditions for registration to ensure they meet the necessary standards and can provide the required information about their structure and key personnel.
Failure to register where required will have serious consequences. Unregistered advisers will not be permitted to act with HMRC for clients. The department may issue formal notices directing them to cease acting and may impose temporary or permanent bans on registration. Continued interaction after a stop notice could also result in financial penalties. For firms that rely on HMRC engagement as part of their service delivery, timely registration will therefore be critical to avoid disruption and reputational risk.
Overall, the new ASA registration regime represents a shift towards greater regulation of the tax advice sector. While many established advisers already hold agent services accounts and will experience minimal change, others who have historically interacted with HMRC only occasionally or incidentally may now find themselves within scope. Reviewing current client interactions and preparing for registration ahead of the relevant deadline will ensure continued compliance and uninterrupted support for clients as HMRC’s new framework takes effect.
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