Authorising an adviser during a tax enquiry

Authorising an adviser during a tax enquiry should establish the scope of representation and the official HMRC authority needed. Agree who handles correspondence, approves responses and monitors deadlines while ensuring the taxpayer understands the facts being submitted.

Keep specialist advice needs separate from routine account access. Do not share personal HMRC credentials, and clarify responsibility where an existing accountant and a dispute specialist both act.

Define the representation you actually need

Identify the tax, periods and current stage of the enquiry before appointing an adviser. Explain whether assistance is needed with bookkeeping evidence, technical analysis, correspondence, a penalty dispute or potential tribunal proceedings. These tasks can require different experience and a different engagement scope. A firm preparing annual returns may not already be instructed to handle every aspect of a newly opened dispute.

Ask for a written description of the work, the responsible contact and how additional tasks will be agreed. Include the immediate response date and any formal notices already received. This allows the adviser to assess urgency and suitability before the taxpayer assumes representation is in place. If specialist legal input may be required, identify that need early rather than treating routine account access as sufficient preparation for every issue.

Complete the appropriate HMRC authority

HMRC allows taxpayers to authorise an agent or, through other arrangements, a friend, relative or another representative to help deal with their affairs. The appropriate method depends on the role and service concerned. ^[1] Follow the official process for the relevant tax and confirm that it has been completed. A signed commercial engagement and HMRC's authority to discuss information are related but separate steps.

Do not share personal sign-in credentials or ask an adviser to impersonate you in an online account. Keep confirmation of the authorisation and record which taxes and entities it covers. Where the enquiry concerns a company, check that the authority relates to that company rather than only to a director's personal Self Assessment. If several entities are involved, maintain a separate authority record for each relevant taxpayer.

Coordinate existing and new advisers

Explain whether another accountant continues to prepare returns or maintain the bookkeeping. Agree who supplies original records, who develops technical arguments and who sends responses to HMRC. A clear division helps prevent duplicate letters, conflicting explanations or an assumption that someone else has dealt with a notice. Give both advisers the same verified chronology and identify the final version of any calculation being discussed.

Arrange a structured handover of returns, computations, correspondence and unresolved questions. Keep a record of what has actually been transferred and any access still outstanding. If an earlier adviser prepared a disputed figure, ask for the supporting working papers and factual explanation without assuming either that the figure is correct or that an error has occurred. The new representative needs evidence before forming a view.

Agree approvals and communication channels

Decide how factual statements and proposed responses will be checked with you before submission. Nominate a business contact who can confirm transactions and locate records, and agree how urgent approvals will be handled if that person is unavailable. The representative can organise the response, but the factual account still needs to reflect what happened. Flag statements based on recollection so they can be checked against documents where possible.

HMRC's guidance explains that some correspondence may still be sent directly to the taxpayer, including tax bills or refunds in the Self Assessment context. ^[1] Continue checking post and online messages, and forward relevant items promptly. Do not assume that agent authorisation means every document will reach the adviser automatically. Keep a shared record of deadlines, submissions and agreed next steps to prevent gaps between the two channels.

Review authority and scope as the enquiry develops

If the matter moves from an information request to a formal decision, penalty or appeal, confirm whether the existing engagement covers the next stage. Ask about any additional specialist work and the evidence needed before a deadline becomes urgent. Keeping a timeline of HMRC correspondence provides a method for maintaining the correspondence timeline that both taxpayer and representative can use. A change in scope should be documented rather than inferred from an informal conversation.

To discuss assistance with a tax enquiry, see HMRC enquiry response support. Provide the opening letter, latest notice and nearest deadline through the agreed initial process. Confirm who will take responsibility before relying on the service to respond. If representation ends or changes, address HMRC authority, document transfer and outstanding dates expressly so the case does not lose continuity during the transition.

Keep a final list of open actions at every handover: the task, owner, due date and supporting reference. Ask the incoming adviser to confirm receipt and identify anything they cannot yet accept. This practical step protects the response process from assumptions about access or responsibility while allowing the substantive work to continue on a clear basis.

Illustrative scenario

A company appoints a specialist for an enquiry while its regular accountant continues annual compliance. The engagement records who answers HMRC and who supplies the underlying schedules.

Preparation checklist

• Confirm representation scope
• Complete official authority
• Assign deadline monitoring
• Agree response approval