Need help submitting your 64-8 form?
The 64-8 form is what allows HMRC to speak directly with your accountant or tax agent about your company’s affairs. It’s the official authorisation that lets them file returns, access your tax records, and handle HMRC correspondence on your behalf.
Explore Sleek’s accounting services to see how our experts manage HMRC authorisations and filings for UK companies.
Getting this form right saves time and prevents HMRC delays or missed deadlines. In this guide, you’ll learn:
- What the 64-8 form covers
- How to complete and submit it correctly
- How online agent authorisation works
- What happens after submission and how to change or revoke access
Need help submitting your 64-8 form? Authorise your accountant quickly with Sleek.
The basics of the 64-8 form
The 64-8 form lets you give formal permission for a tax agent or accountant to deal with HMRC on your behalf. Once HMRC accepts it, your agent can:
- File and amend your tax returns
- Access your company’s tax records
- Discuss payments, refunds, and compliance queries directly with HMRC
You can use the 64-8 form to cover most UK taxes, including:
- Corporation Tax
- VAT
- PAYE for employers
- Self Assessment
- Construction Industry Scheme (CIS)
It’s an important step because HMRC won’t discuss your tax affairs with anyone who isn’t officially authorised. The form effectively gives your agent the green light to manage everything related to your company’s taxes, so you can focus on running your business.
If you’re setting up a limited company, it’s best to authorise your accountant as soon as you register. Learn how in our guide to company registration.
Key areas covered by the 64-8 form
The 64-8 form lets your accountant or tax agent manage several parts of your tax affairs with HMRC. Each area of authorisation is specific, so you can choose exactly what access to grant.
Self Assessment
Your agent can file and amend Self Assessment returns, view your tax calculations, and manage HMRC correspondence. They can also update your details or cancel your registration when needed.
PAYE for employers
For employers, the 64-8 form allows your agent to handle payroll-related tasks such as reviewing PAYE records, updating employee details, and discussing tax codes or deductions with HMRC.
Corporation Tax
When authorised for Corporation Tax, your accountant can submit CT600 returns, update company details, and handle payment or penalty queries. To understand how trading status affects filing duties, see Trading vs Non-Trading for Corporation Tax in the UK.
VAT
Agents can manage VAT registration, prepare and submit VAT returns, and speak with HMRC about compliance matters. For what happens if you miss a payment, check Understanding VAT Late Payment Penalties.
CIS (Construction Industry Scheme)
If you work in construction, the form enables your agent to manage CIS returns, verify subcontractors, and reconcile deductions accurately.
Once HMRC processes your authorisation, your agent’s access is recorded digitally, allowing them to manage your tax accounts efficiently without constant re-approval.
Keep a digital copy of your signed 64-8 form so you can re-authorise or update your agent quickly if needed.
Completing the 64-8 form: step-by-step guide
Filling in the 64-8 form is simple once you know what HMRC needs. It’s split into three main sections covering your details, your agent’s details, and the specific taxes they’ll manage.
Step 1: Add your personal or company details
Start with your full name or company name, address, and contact information.
If you’re a company, include your registration number and Unique Taxpayer Reference (UTR).
These details must match exactly what HMRC has on file. Even small mismatches can delay processing.
Step 2: Provide your agent’s information
Next, enter your accountant or tax agent’s details, including their business name and address.
You’ll also need their HMRC agent code, which identifies them in the system. Without this code, HMRC cannot link your authorisation to the correct account.
If you’re still choosing a professional, Sleek’s accounting services include full HMRC authorisation setup as part of onboarding.
Step 3: Select the taxes your agent can manage
Tick the boxes for each area you want to authorise, such as Self Assessment, Corporation Tax, or VAT.
If you’re authorising multiple services, make sure all relevant boxes are marked before signing.
For Corporation Tax, include the company’s UTR.
For VAT, include your VAT registration number.
For CIS, list your employer reference if you have one.
Step 4: Sign and date the form
Both you and your authorised agent must sign the form. HMRC usually requires original signatures, not photocopies or scans, when submitting by post.
Electronic authorisation is available for online requests, covered in the next section.
Step 5: Double-check before submitting
Before sending, confirm that:
- All reference numbers match HMRC’s records
- The correct taxes are ticked
- Both signatures are included
A final check helps you avoid delays or rejections.
Submitting the 64-8 form to HMRC
Once the 64-8 form is complete and signed, you can send it to HMRC either online or by post. The method you choose depends on whether your accountant uses HMRC’s agent portal.
Online submission
Most agents now handle authorisation online. They’ll send you a digital link through HMRC’s portal, which you approve using your Government Gateway account. This is the fastest option. Approval is often confirmed within 72 hours, and you’ll receive an email or HMRC letter once the link is active.
If you have not yet registered for an HMRC online account, you can do so using your company’s UTR. You can find guidance in our Corporation Tax registration guide.
Postal submission
If you prefer, you can print and post the form to HMRC. Use the latest version of the 64-8 form available on GOV.UK – Authorise a tax agent (form 64-8). Send it to:
Central Agent Authorisation Team
HM Revenue and Customs
National Insurance Contributions and Employer Office
HMRC, BX9 1AN, United Kingdom
Always post the original document with wet signatures. HMRC does not accept photocopies or scans for postal submissions.
After submission
HMRC will notify both you and your agent once the authorisation is active. From that point, your accountant can manage your tax accounts directly. If there are any discrepancies, HMRC may request additional verification before approval.
64-8 form processing time and HMRC notifications
HMRC usually processes online 64-8 authorisations within two to three working days. Postal submissions can take up to two weeks, depending on workload.
You and your agent will both receive confirmation once the authorisation is active. If you do not hear back after two weeks, contact HMRC’s Agent Services helpline to check the status.
Responsibilities and limitations when authorising an agent
When you submit a 64-8 form, you give your tax agent permission to act for you with HMRC. This access comes with clear boundaries.
What your agent can do
Your authorised agent can:
- File and amend your tax returns
- Discuss your account with HMRC officers
- Receive copies of correspondence
- Update your contact details or bank information for repayments
These permissions make it easier for your accountant to manage deadlines and handle HMRC directly.
What your agent cannot do
Your agent cannot make legal decisions for your business or access unrelated accounts. Authorisation applies only to the taxes you selected on the form. You remain legally responsible for the accuracy of all information submitted.
To keep things running smoothly, review your authorisation once a year and update it if your business circumstances change.
Changing or revoking a 64-8 authorisation
If you change accountants or no longer need representation, you can cancel your 64-8 authorisation at any time.
How to revoke access
You can withdraw your agent’s authorisation either online through your HMRC account or by writing to the Central Agent Authorisation Team.
Once HMRC processes your request, your agent’s access is removed immediately.
How to appoint a new agent
If you’re switching accountants, simply submit a new 64-8 form with your new agent’s details. HMRC will automatically replace the previous authorisation.
Benefits of using a professional tax agent
Authorising a qualified accountant through a 64-8 form does more than save you admin time. It reduces the risk of missed deadlines, incorrect filings, and HMRC penalties.
A professional agent will:
- Ensure returns and payments are made on time
- Handle correspondence directly with HMRC
- Keep your business compliant with changing tax laws
Using a trusted agent gives you confidence that everything from VAT to Corporation Tax is handled correctly. You can learn more in our guide on accountant costs for small businesses.
Digital authorisation and Making Tax Digital
HMRC now supports digital agent authorisation through its Agent Services Account. Instead of paper forms, you approve your accountant’s access online using a secure link.
This digital process aligns with Making Tax Digital (MTD), which requires most businesses to keep and submit tax records electronically. Digital authorisation helps you stay compliant while reducing paperwork.
If your accountant manages your MTD submissions, they’ll handle this online authorisation as part of the setup.
Special cases and data protection
Certain circumstances need extra care when using the 64-8 form.
Deceased persons or estates
Only a legally appointed executor can authorise an agent to manage tax affairs on behalf of a deceased person. The executor must include proof of their authority when submitting the form.
Multiple agents
You can appoint different agents for different taxes, such as one for payroll and another for VAT. Each requires its own 64-8 form.
GDPR and data security
By signing the form, you agree that HMRC can share relevant tax information with your authorised agent. Agents must handle all data securely and comply with GDPR rules.
How Sleek keeps you compliant with the 64-8 form and beyond
Once your 64-8 form is approved, HMRC can communicate directly with your accountant. That means fewer delays, less admin, and smoother tax management for your business.
With Sleek, you’ll get full support from setup to submission. Our team ensures your authorisation is completed correctly, your filings stay on time, and your company remains compliant with every HMRC requirement.
Need help submitting your 64-8 form? Authorise your accountant quickly and correctly with Sleek’s expert support.
FAQs on the 64-8 form in the UK
What is a 64-8 form used for?
The 64-8 form lets you officially authorise an accountant or tax agent to deal with HMRC on your behalf. Once accepted, your agent can file returns, discuss your taxes, and access your records.
Who needs to fill out a 64-8 form?
Any individual or business that wants an accountant, bookkeeper, or tax agent to communicate directly with HMRC must complete and sign a 64-8 form.
What’s the difference between a 64-8 form and agent authorisation online?
The 64-8 form is the traditional paper-based method, while agent authorisation online is the digital version managed through HMRC’s Agent Services Account. Both serve the same purpose but the online method is faster.
Can I submit a 64-8 form online or by post?
Yes. You can approve authorisation online through your Government Gateway account or post a signed paper form to HMRC’s Central Agent Authorisation Team.
What are common mistakes when submitting form 64-8?
Missing UTR or VAT numbers, incorrect agent codes, and unsigned forms are the main causes of rejection. Always double-check before submitting.
How to remove an agent after submitting a 64-8 form?
You can revoke access online through your HMRC account or by writing to HMRC. Once processed, the agent’s access ends immediately.
HMRC address for sending 64-8 form
Send the completed and signed form to:
Central Agent Authorisation Team, HM Revenue and Customs, BX9 1AN, United Kingdom.
Hire a tax agent who can file a 64-8 form
Sleek’s accountants can complete and submit your 64-8 form, set up digital authorisation, and manage all HMRC correspondence for you. Learn more about Sleek’s accounting services.
Disclaimer: The preceding information is not legal advice. This content is aimed to provide general guidance. For more formal or legal advice, contact Sleek directly.
