HMRC explains how to authorise an accountant to deal with your tax affairs

HMRC publishes guidance on GOV.UK about authorising an agent, meaning a paid representative such as an accountant or tax adviser. The page has existed since 4 April 2014. It was last updated on 6 October 2026, when information about a new online tool with extra VAT guidance was added.

How to authorise an agent

The method depends on which tax services you and your agent use. HMRC points to a separate page listing all the ways of authorising an agent for each tax. The guidance reminds taxpayers that they remain legally responsible for their own tax. If your agent submits your tax return, you must check the information and confirm to them that it is correct before they send it.

If you cannot authorise an agent through an online service or your business tax account, you use the paper form "64-8 Authorising your agent". You need to print it or fill it in on screen, sign and date it, and post it to the address shown on the form. HMRC asks, among other things, that you fill it in clearly, give the correct agent codes, write nothing outside the boxes, and not include a covering letter unless it contains essential information.

What an agent can do

The scope depends on the tax. For Self Assessment, an authorised agent can, among other things:

• submit tax returns on your behalf,
• claim tax reliefs,
• discuss your current and previous returns with HMRC,
• change your details, such as sources of income,
• provide bank details when a repayment is due,
• cancel your Self Assessment registration.

Before you authorise an agent, you must first register for Self Assessment. For Making Tax Digital for Income Tax, an agent can sign you up, keep digital records of your self-employment and property income and expenses, send quarterly updates, and submit your tax return and pay the tax due by 31 January the following year.

For VAT, an agent can (in writing or by telephone only) discuss your VAT with HMRC, change your details, view payments, cancel your registration and appeal against penalties. For individual PAYE, form 64-8 gives the agent access to, for example, your past employers, benefits and pensions. For tax credits, the agent can see your information but cannot receive payments, and letters still go to you. For a joint claim, both claimants must sign.

Limited authorisation and compliance checks

You can also give an agent limited authorisation. The agent can then speak to HMRC and help you fill in forms, but has no access to your tax online. This requires a letter to HMRC with your name and address, your tax reference number (for example your UTR), the agent's name and address, and your signature. HMRC no longer accepts form 64-8 for this kind of limited authorisation.

A separate form, COMP1a, is used to authorise an agent during an HMRC compliance check. Authorisation can be changed or removed on a separate GOV.UK page.

What this means for you

Many people who are self-employed, let out property or file their own returns use accountants. The guidance shows that before you hire an agent, it is worth checking which method is used to authorise them for each tax, and remembering that responsibility for your tax return stays with you. The guidance covers paid agents. There is a separate process for a friend or relative who is to deal with HMRC for you.