HMRC has updated its guidance on authorising a paid agent to deal with tax affairs, a useful reminder for small business owners who rely on accountants, bookkeepers or payroll specialists to handle filings and correspondence.
The GOV.UK page, updated on 10 July 2026, explains that a paid agent can deal with HMRC on a taxpayer’s behalf, but the way that authority is given depends on the tax involved. In some cases a business can use an online service. In others, HMRC may still require paper form 64-8.
That detail matters because many small firms assume that appointing an adviser commercially is enough. It is not. HMRC needs the right authorisation in place before it can discuss a company’s tax position, process some requests, or allow an adviser to act through the relevant online service.
Why this matters for SMEs
For a small company, sole trader or partnership, agent authorisation is often treated as admin that can wait until a deadline is close. That can create unnecessary risk. If a new accountant cannot access the right tax service, routine work such as checking a Self Assessment position, helping with VAT, dealing with PAYE queries or managing Corporation Tax correspondence can take longer than expected.
The issue can be especially awkward when a business is changing advisers, bringing payroll support in for the first time, or asking a bookkeeper to take on wider tax administration. The business may think the handover is complete, while HMRC still sees no valid authority for the new agent.
HMRC’s guidance is also a prompt to check exactly what an agent is being authorised to do. A business may want one adviser to handle VAT, another to handle payroll, and an accountant to deal with year-end tax. Each service may have its own process and scope, so owners should avoid assuming that one authorisation covers every tax area automatically.
What to check now
Small businesses that use a paid adviser should make a simple record of who is authorised for each tax area, which HMRC service was used, and when the authority was set up. That record can save time during staff changes, adviser changes or deadline pressure.
It is also worth checking whether old agents still have access. If a previous accountant, payroll bureau or bookkeeper no longer works for the business, the owner should review access and remove anything that is no longer needed. That is both a data protection issue and a practical control over who can see or act on business tax information.
Where a new agent is being appointed, build in time for the authorisation process before key filing dates. Online authorisations can still involve verification steps, while paper routes may take longer. Leaving it until a return, payment or query is urgent can turn a routine handover into a deadline problem.
Practical takeaway
The update is not a major policy change, but it is a timely nudge for small firms to tidy up tax access. Treat agent authorisation as part of supplier onboarding, not as a one-off formality handled in the background.
Owners should ask their adviser which HMRC services they need access to, confirm the correct route for each tax, and keep evidence of what has been authorised. If there is any doubt, the GOV.UK guidance should be the starting point, because it sets out when online services can be used and when form 64-8 may be needed.
For small businesses, the practical goal is simple: the right adviser should be able to act when needed, old access should not linger, and tax administration should not stall because authority was missing at the wrong moment.
Source: GOV.UK: Authorising an agent to deal with your tax affairs.
