By Shamayun Chowdhury, Senior Accountant, Major Accountancy · Published: 3 November 2026 · Last reviewed: November 2026 · Reflects HMRC’s 2026 tax adviser registration rules
For years, many accountants and bookkeepers treated the agent services account as something only MTD for VAT needed. That has changed. Making Tax Digital for Income Tax runs through it, and HMRC now requires paid tax advisers to register through it. If you act for sole traders or landlords, the HMRC agent services account has become your main way into HMRC.
This guide follows the account from start to finish: whether you must register, how to apply, what to do at your first agent services account login, how to handle MTD clients inside it, and how to fix the problems agents report most often. A short final section explains what your clients need to do when you ask them to authorise you.
- The agent services account is separate from HMRC online services for agents, and it uses its own Government Gateway user ID.
- Paid tax advisers must register in 2026, with set dates for some groups.
- You need approved anti-money laundering supervision before applying.
- Existing Self Assessment authorisations can be added for MTD for Income Tax, but each client still has to be signed up.
- Clients can have one main agent and several supporting agents for MTD for Income Tax.
What Is an HMRC Agent Services Account?
An HMRC agent services account is the online account a tax adviser’s business uses to deal with HMRC on behalf of clients for certain modern services. The account belongs to the business, the legal entity, rather than to one person, and each member of staff signs in with their own Government Gateway user ID.
HMRC currently runs two agent accounts side by side, and the service you need decides which one you use. GOV.UK lists them on its page of HMRC services for tax agents.
Agent services account vs HMRC online services for agents
| Agent services account | HMRC online services for agents |
|---|---|
| Making Tax Digital for Income Tax (sign-up and authorisations) | Self Assessment for agents |
| Managing client details for VAT (MTD for VAT) | Corporation Tax for agents |
| Capital Gains Tax on UK property accounts | PAYE for agents, including CIS |
| Registering trusts and estates | Legacy VAT online services |
| Income Record Viewer | Annual Tax on Enveloped Dwellings, Gambling Tax and Machine Games Duty |
| Pillar 2 Top-up Taxes | Notification of Vehicle Arrivals |
The two accounts use different sign-in details. Mixing them up is the single most common reason agents get stuck at the login page.
Do You Have to Register? The 2026 Tax Adviser Rules
HMRC has introduced a legal requirement for paid tax advisers to register. If you interact with HMRC about someone else’s tax affairs and are paid for it, HMRC treats you as a tax adviser, and you need an HMRC agent services account. The rules are set out in HMRC’s guidance to check if and when you need to register as a tax adviser.
Interacting with HMRC includes phone calls, letters, emails, messages through GOV.UK or the HMRC app, making payments and sending returns or claims. You still need to register if you work as a sole trader, act for just one client, or do not think of yourself as a tax adviser.
Who does not need to register
- employers and in-house tax teams dealing with their own staff or their own group
- people giving free help, for example through a charity or for friends and family
- people who must deal with HMRC because the law requires it, even if paid, such as insolvency practitioners and some pension or investment firms
- software developers, and anyone only responding to an HMRC information request
- those dealing only with customs or import VAT, or acting as a VAT representative
- a Northern Ireland tax representative appointed by a business outside the UK
- a UK representative appointed by an overseas business for Vaping Duty
- an intermediary for the Import One Stop Shop (IOSS) scheme
- anyone only representing a client in appeals to a court or tribunal
- anyone only dealing with HMRC about business rates, council tax or property valuation
When to register
| Your situation | When you must register |
|---|---|
| New to acting for clients, or missed your window | Now |
| You already have a Self Assessment or Corporation Tax agent code | From 18 August 2026 |
| You only provide third-party payroll services | From 18 November 2026 |
| You are a financial services organisation | From 31 December 2026 |
| You already have an agent services account | No need to register again. HMRC will contact you through the account to check you meet the conditions |
You have three months from the date your window opens to apply, and you can keep acting for clients during that time and while HMRC considers your application. If you need to register and do not, you may lose the ability to deal with HMRC for clients and could face sanctions, although HMRC says it will give you a chance to put things right first.
If you already hold an account, HMRC has said it will contact existing holders through their agent services account between January and March 2027 to check them against the new registration conditions, so keep an eye on your account messages.
Our page on MTD for accountants and agents explains how Making Tax Digital changes day-to-day practice work.
How to Apply for an HMRC Agent Services Account
Before you start, read HMRC’s conditions for registering as a tax adviser, then gather the details below. They come from HMRC’s guidance to apply for an agent services account.
| What you need | Notes |
|---|---|
| Business Government Gateway user ID and password | You can create one on the sign-in page |
| Personal Government Gateway user ID | Needed if you are a sole trader |
| Unique Taxpayer Reference (UTR) for the business | Plus the postcode linked to that UTR |
| Company registration number | If the business is a limited company |
| VAT registration number | If the business is VAT registered |
| Anti-money laundering (AML) supervisor and proof of supervision | Supervision must already be approved |
| Names and contact details of relevant people | HMRC carries out checks on certain individuals |
The application, step by step
- Check you need to register using HMRC’s online tool and your registration window.
- Check you meet HMRC’s conditions for registering as a tax adviser.
- Sign in with the business Gateway ID, not a personal or staff ID.
- Complete the details and share the link the service gives you with the relevant people in your business. They must sign in with their own Gateway IDs.
- Submit and track progress. GOV.UK has a link to check an existing application.
How long it takes
HMRC does not publish a fixed timescale. Applications take longer if HMRC needs more information or extra checks. If you are applying within your registration window, you can carry on acting for clients while you wait.
If your business is outside the UK
If your business or any relevant individuals operate outside the UK, HMRC requires authenticated evidence that the registration conditions are met. Documents must be notarised by a qualified independent notary, or equivalent, and translated into English if needed. Do not send them until HMRC tells you to. Overseas businesses must use the existing registration route.
What Standards Must Agents Follow?
Holding an HMRC agent services account does not mean HMRC approves of your business. You must not use it to suggest that HMRC endorses you, that you are part of HMRC, or that you act on HMRC’s behalf. You also need to keep meeting the registration conditions for as long as you act for clients, however your business works with HMRC.
Agent Services Account Login: First Steps After Approval
Once you are approved, sign in through HMRC’s official agent services account sign-in page, using the Gateway ID for the account. Bookmark that GOV.UK page rather than a search result, so you always reach the genuine service. Do this before you take on MTD work, so that your setup is in place before deadlines arrive.
- Create a Government Gateway user ID for each member of staff. Do not share the business login.
- Set permissions to control which services and clients each person can see.
- Keep your agent reference number (ARN) safe. HMRC may ask for it when you submit certain Income Tax or PAYE repayment claims on behalf of clients.
- Request client authorisations for any clients who have not authorised you yet.
How Do You Use an Agent Services Account for Making Tax Digital?
HMRC’s MTD for Income Tax as an agent step-by-step guide sets out seven stages. The parts that happen inside your HMRC agent services account are explained below.
Add your existing Self Assessment authorisations
Your existing Self Assessment authorisations are recognised for MTD for Income Tax. In your account, choose “Add existing Self Assessment authorisations to your agent services account” and enter your Self Assessment agent code. This adds every client linked to that code. HMRC explains the process on its page to add your client authorisations.
- The list shows agent codes you have added, not individual clients.
- Adding authorisations does not remove access in your online services account, so you can still file Self Assessment there.
- It does not sign anyone up for MTD. Each client still needs to be signed up.
- Clients added this way are treated as having you as their main agent.
Ask new clients to authorise you
If a client has not authorised you for Self Assessment, use your agent services account to send them an authorisation request. The client receives a link and accepts it, a process HMRC calls a digital handshake. Clients authorised this way do not need to be added through an agent code.
Main agent or supporting agent?
A client can appoint one main agent and any number of supporting agents for MTD for Income Tax. This arrangement applies to MTD for Income Tax only; for other services, such as Self Assessment, the client can have only one agent. Supporting agents can sign a client up and submit quarterly updates, but they cannot finalise the overall tax position or submit the tax return. HMRC explains the split on its page about choosing agents for MTD for Income Tax.
| Task | Main agent | Supporting agent |
|---|---|---|
| Sign a client up for MTD for Income Tax | Yes | Yes |
| Send quarterly updates of business and property income | Yes | Yes |
| See all of a client’s income sources | Yes | No |
| Finalise the tax position and submit the tax return | Yes | No |
| View tax calculations and amounts owed | Yes | No |
| Receive copies of statutory letters and penalty notices | Yes | No |
| Set up a client’s Direct Debit | No | No |
A common split is a bookkeeper acting as a supporting agent for quarterly updates, with the accountant as main agent for the tax return. If several agents work on one business, they must make sure a single combined update is sent for each period.
Sign each client up for MTD for Income Tax
Use the online service to sign up your client for MTD for Income Tax, signing in with your agent services account details. You will need the client’s full name, date of birth and National Insurance number. For sole traders, you also need the business name, address and trade, plus start dates for any income source that began in the last two tax years.
From September 2026, HMRC began signing up people who need to use MTD for 2026/27 and had not signed up themselves, where its records show qualifying income over £50,000 on their 2024/25 tax return. It uses only the information it already holds. Signing clients up yourself lets you check their income sources are correct. Before you start, check whether the client is covered by any Making Tax Digital exemptions.
MTD for VAT clients
For VAT, the agent services account is where you manage client details and connect compatible software. You can copy existing VAT client relationships across from your online services account and authorise new clients from within the account. Our page on MTD for VAT covers the VAT rules in more detail.
1. Check their qualifying income and start date.
2. Confirm you are authorised, through an agent code or a digital handshake.
3. Agree which software you will use.
4. Sign them up through the online service, checking every income source.
5. Diary the quarterly update deadlines and the tax return date.
Agent Services Account Not Working? Common Problems and Fixes
| Problem | Likely cause | What to try |
|---|---|---|
| You are asked to create an account you already have | Signed in with your HMRC online services for agents ID | Sign out and use the agent services account Gateway ID, or try another browser |
| The service will not load | HMRC system issue or maintenance | Check HMRC’s service availability page |
| A client is missing from MTD for Income Tax | Their Self Assessment agent code has not been added | Add the agent code, or send a new authorisation request |
| You cannot sign a client up | You are not authorised, or details do not match HMRC’s records | Confirm the authorisation, then check the NINO, name and date of birth |
| Your application is rejected | AML supervision not approved, or conditions not met | Wait for AML approval and recheck HMRC’s conditions |
| A colleague cannot see a client | Their Gateway ID lacks the right permissions | Update their access in the account |
If you still cannot get in, contact HMRC’s online services helpdesk for technical problems with Government Gateway sign-in. Check GOV.UK for current phone numbers, because they change from time to time.
For Business Owners: How Do You Authorise Your Accountant?
If your accountant asks you to authorise them, you will usually receive a link. Open it, sign in with your own Government Gateway details or HMRC account, and accept the request. The wording you see explains what the agent will be able to view and do, so read it before you agree.
Authorising an agent does not hand over legal responsibility. You remain responsible for your tax, so keep your records accurate and reply to your agent promptly. To remove an agent later, use the manage your tax agent option in your HMRC account.
MTDFix handles the authorisation, sign-up and quarterly updates for sole traders and landlords, so you do not have to work through these screens yourself. See our guides to MTD for Income Tax and signing up for Making Tax Digital.
HMRC Agent Services Account FAQs
What is an HMRC agent services account?
It is the online account tax advisers use to act for clients in HMRC services such as Making Tax Digital for Income Tax, MTD for VAT client details, Capital Gains Tax on UK property, trusts and estates. It belongs to the business, and staff sign in with their own IDs.
Can I use my HMRC agent services account for Self Assessment?
Not for filing. Self Assessment returns are still filed through HMRC online services for agents. You can add your Self Assessment agent codes to your agent services account so those authorisations work for MTD for Income Tax, and the 2026 rules mean most paid advisers need an agent services account anyway.
Is the agent services account the same as HMRC online services for agents?
No. They are separate accounts with different Government Gateway user IDs, and each one gives access to different HMRC services.
When do I need to register as a tax adviser?
Most new advisers should register now. Holders of Self Assessment or Corporation Tax agent codes register from 18 August 2026, payroll-only agents from 18 November 2026, and financial services organisations from 31 December 2026.
Can a sole trader bookkeeper get an agent services account?
Yes. A sole trader who is paid to deal with HMRC for clients needs to register, using both a business and a personal Government Gateway ID, and must have approved AML supervision.
How long does HMRC take to approve an agent services account?
HMRC does not give a fixed time. It can take longer if extra checks are needed, but you can keep acting for clients during your registration window while HMRC considers your application.
Why does HMRC keep asking me to create an agent services account?
Usually because you have signed in with your HMRC online services for agents user ID instead of your agent services account ID. Sign out, use the correct ID, or try a different browser.
Final Word on the HMRC Agent Services Account
The HMRC agent services account is now central to working as a paid tax adviser. Register within your window, make sure AML supervision is approved first, add your Self Assessment agent codes, and sign each MTD client up individually. Keep staff access tidy and you will avoid most of the problems agents run into.
Written by Shamayun Chowdhury, with every requirement, date and process checked against HMRC guidance on GOV.UK in November 2026; the date for HMRC contacting existing account holders comes from CIPP’s May 2026 report of HMRC’s announcement. No separate technical reviewer is named. HMRC updates its agent services regularly, so check the linked pages before acting. This guide is general information, not advice for your circumstances.