Compliance
How U.K. Tax Advisers Must Register from May 2026: What Advisers & Clients Need to Know
HMRC is mandating registration for all paid tax advisers interacting with clients on tax matters. Here’s how it works, who it applies to, and how both advisers and clients are affected.
By NomadicTax Research Team • 5-8 min read • June 22, 2026
## Background: Why the Change?
From **18 May 2026**, the U.K. Government rolled out a new registration requirement for tax advisers who are **paid to interact with HM Revenue & Customs (HMRC)** on behalf of clients. This policy, known as **MMTAR** — Modernising and Mandating Tax Adviser Registration — had been announced in the 2025 Budget and follows consultations throughout 2024. ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
The goals are to increase transparency, raise standards in the tax advice market, and simplify both compliance and oversight for HMRC. Adviser registration replaces earlier fragmented workflows. ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
## Who Must Register and When
**Who**:
* Any individual or firm **paid to give tax advice and interact with HMRC on behalf of clients** — this includes overseas tax advisers who serve U.K. taxpayers. ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
* Certain services, like payroll-only or limited activities, may **initially be exempt** or follow a phased timeline. ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
**When**: Phased implementation through **March 2027**, split by adviser category: new advisers first, then those with certain existing HMRC accounts, then payroll-only and financial service organisations. ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
## Effects on Advisers
* **Compliance costs**: Need to apply for an **Agent Services Account (ASA)** if not already registered.
* **Identity and background checks**: Provide personal identifiers (e.g., NI number, proof of firm registration, AML supervisory body if needed). ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
* **Restriction for non-compliant promoters**: Advisers with outstanding promoter penalties or other non-compliance may be **barred from using HMRC systems** to represent clients. ([assets.publishing.service.gov.uk](https://assets.publishing.service.gov.uk/media/6925eb772945773cf12dd09a/Loan_Charge_Review_2025_-_Government_Response_.pdf?utm_source=openai))
## Implications for Clients
* Better protection: clients can verify that adviser is registered; when adviser’s identity is clear, risk of fraud or misleading advice is reduced.
* Easier accountability: HMRC can enforce rules against unregistered advisers acting in bad faith.
* Possibly limited adviser options: Advisers unwilling or unable to register may no longer work with clients in certain capacities.
## Practical Advice & Action Steps
1. **If you’re an adviser**:
* Check whether your services qualify under HMRC’s definition: paid advice + interacting with HMRC.
* Apply for register during your assigned window. Missing it may restrict ability to act for clients.
* Ensure **anti-money laundering (AML) clearance** and other compliance elements are in place.
2. **If you’re a taxpayer seeking advice**:
* Ask your adviser if they are registered under MMTAR (or applying) before engaging services.
* Review Adviser’s ASA details when available.
* Keep documentation of advice and correspondence—important in case of disputes.
## Example Scenarios
* **Overseas Advisor**: An accountant in Spain giving tax advice to a U.K. taxpayer must register under MMTAR if paid and interacting with HMRC. Ignoring this could mean lost access for clients to HMRC systems.
* **Payroll-only service**: A small firm running payroll may be exempt early but will have a registration window between **November 2026 and February 2027**. Missing that could bring sudden disruption. ([gov.uk](https://www.gov.uk/government/news/tax-advisers-check-if-you-need-to-register-under-new-rules?utm_source=openai))
## Final Word
This is a compliance policy with **high impact** across the advisory industry. Whether you give or receive tax advice, this change establishes a clearer, more consistent standard. Registered advisers will be those who adhere to rules—and that benefits clients, the tax system, and the adviser profession itself.