64-8 form: authorise your agent with HMRC

64-8, online authorisation or a letter?

How to complete and send form 64-8

1. 1

   Register for the tax first

   For Self Assessment, register before you authorise an agent. If your Unique Taxpayer Reference has not been issued yet, tick the box on the form.

2. 2

   Download and fill in the current form

   Download and save the form, open it in the latest free Adobe Reader, then fill it in on screen and print it, or print it and write clearly.

3. 3

   Sign and date it

   The person in the 'Who should sign' table signs: you for your own affairs, the secretary or another responsible officer for a company, the responsible partner for a partnership, or one or more trustees for a trust.

4. 4

   Post pages 1 and 2 to HMRC

   Use the postal address on the form. Keep page 3 for your records, and send any covering letter only if it holds essential information.

Form 64-8 section by section

The current form is three pages: your details and declaration, your agent's details, then one box per tax. Tick only the taxes your agent will handle.

Your name, business and address

Print your name, the business, company or trust name if applicable, and your personal address or the company's registered office, with a phone number.

Declaration, signature and date

By signing you confirm the agent has agreed to act for you and that the authority is limited to the matters ticked on the form.

Agent's details and agent codes

Give the agent's business name, address and phone number. In the 'Agent code (SA)' field include only the agent's Self Assessment code; HMRC says not to add anything else to a field.

Self Assessment and Partnership

Ticking Self Assessment needs your National Insurance number and/or UTR; Partnership needs the partnership UTR. You can also ask HMRC to send your Statement of Account to the agent, but paying any amount due stays your responsibility.

Trust and Individual PAYE

Give the trust's UTR, or your National Insurance number for Individual PAYE. GOV.UK says the 64-8 does not give an agent access to the online trust service; that is authorised online.

Corporation Tax

Give the company registration number and the company's UTR. The agent can then see company and financial information and update communication and contact details.

Tax credits

Give your National Insurance number. For a joint claim, the other claimant must add their name, National Insurance number and signature.

VAT and VAT DIY Housebuilder Scheme

Give the VAT registration number, or tick if not registered yet. The agent can deal with HMRC in writing or by phone; submitting VAT returns online needs authorisation through your business tax account.

CIS and employers' PAYE

Give the PAYE reference, the agent's Government Gateway identifier and PAYE agent ID code, and tick whether the agent may use online services, phone and writing, or both.

Mistakes HMRC asks you to avoid

• Using an old or different authorisation form instead of the current '64-8 Authorising your agent'.
• Writing anything on the form outside the boxes, or adding extra information to a field.
• Giving the wrong agent code for a tax, or leaving it unclear which tax each code belongs to.
• Striking through unused boxes: HMRC asks you not to.
• Forgetting to sign and date the form before posting it.
• Sending a 64-8 to ask for limited authorisation, which HMRC no longer accepts.