Agent authorisation: apply using HMRC paper forms
Source: gov.uk (2025-05-12)

How to use paper forms to set up agent authorisations to deal with HMRC.

Overview

If you act as a tax agent or adviser, you must have formal authorisation (https://www.gov.uk/client-authorisation-an-overview) to deal with HMRC on your client’s behalf.

It’s easiest to do this online using HMRC Online Services (https://www.gov.uk/applying-for-client-authorisation-using-hmrc-online-services). If you cannot set up authorisation online, you’ll need to get your client to complete one of HMRC’s paper authorisation forms.

There are 2 types of paper form, these are:
- 64-8 ― for authorisation
- CH995 ― for High Income Child Benefit Charge matters
Your client will need to enter your relevant agent code or reference number (https://www.gov.uk/client-authorisation-an-overview#agent-codes-and-reference-numbers) for authorisations on form 64-8.

Being authorised as an agent will not transfer any of your client’s legal obligations to you.

Form 64-8

Your clients can use form 64-8 (https://www.gov.uk/government/publications/tax-agents-and-advisers-authorising-your-agent-64-8) to authorise you to act on their behalf for:
- individual, partnership and trust tax affairs
- requests to HMRC for information on the High Income Child Benefit Charge to help calculate the charge
- tax credits
- Corporation Tax
- PAYE for employers
- Construction Industry Scheme (CIS) for contractors
- VAT
Your client can authorise you to deal with more than one of these subjects on the same 64-8 form. If your client wants you to act on their behalf for CIS (https://www.gov.uk/payecis-for-agents-online-service), they need to make a note on the 64-8 to say this, or attach a separate letter.

Your client should send the completed form 64-8 to the Central Agent Authorisation Team (https://www.gov.uk/government/organisations/hm-revenue-customs/contact/central-agent-authorisation-team), unless:
- HMRC has asked for a completed 64-8 to be sent to a specific office
- the authorisation is for Corporation Tax only ― send the form to the HMRC office that deals with your client’s Corporation Tax
- HMRC’s High Net Worth Unit deals with your client ― send the form to them
- the authorisation is for a charity ― send the form to the Charities Correspondence Team (https://www.gov.uk/government/organisations/hm-revenue-customs/contact/charities-and-community-amateur-sports-clubs-cascs)
- the authorisation is for a trust’s tax affairs ― send the form to the Trusts and Estates Team (https://www.gov.uk/government/organisations/hm-revenue-customs/contact/trusts)
- the authorisation is for a R40 form repayment claim ― send the 64-8 to HMRC with the R40 (https://www.gov.uk/government/organisations/hm-revenue-customs/contact/r40-where-to-send-repayment-claim-forms)
Tax credits authorisation

You cannot set up tax credits client authorisation online, your client must complete a form 64-8. Joint tax credits claimants must both sign the same 64-8.

HMRC will continue to write to your client about their claim, but you can also deal with HMRC on behalf of your client, in writing or by telephone.

Send the completed 64-8 form to the Central Agent Authorisation Team (https://www.gov.uk/government/organisations/hm-revenue-customs/contact/central-agent-authorisation-team). Do not send it to HMRC with a tax credits claim. Claim forms must be sent to the Tax Credit Office (https://www.gov.uk/government/organisations/hm-revenue-customs/contact/tax-credits-enquiries) separately.

Personal representatives

Personal representatives can use form 64-8 to authorise you to deal with the estate of a deceased person for:
- individual PAYE
- Self Assessment
- National Insurance
The person completing the 64-8 to authorise you to act on behalf of the estate (usually the personal representative) must:
- sign, date and enter their name and address on the authorisation part of the form
- enter the deceased person’s National Insurance number or Unique Taxpayer Reference in the section that covers the type authorisation
What happens next

You can check when you can expect a reply from HMRC (https://www.gov.uk/guidance/check-when-you-can-expect-a-reply-from-hmrc).

Form CH995: for High Income Child Benefit Charge matters

If you need authorisation to deal with your client’s High Income Child Benefit Charge (https://www.gov.uk/child-benefit-tax-charge) matters then they need to complete form CH995 (https://www.gov.uk/government/publications/child-benefit-authorise-a-tax-adviser-for-high-income-child-benefit-charge-matters-ch995).

Form CH995 lets you:
- ask about your client’s Child Benefit payments
- tell the Child Benefit Office if your client decides to stop or restart their Child Benefit payments
- contact the Child Benefit Office about any other Child Benefit related decisions your client makes
Once the authorisation is set up, you’ll be able to deal with your clients Child Benefit in writing, by telephone and online. The Child Benefit Office will continue to send information to your client about their claim.