How to Switch Your UK Accountant Without Losing Compliance

The most common reason Arab directors stay with an accountant they are unhappy with is fear of disruption. What happens to the filings that are in progress? Who holds the Companies House authentication code? Will HMRC authorisation transfer? The answers are: it transfers cleanly, it takes about two weeks, and your compliance position does not lapse during the switch.

Step one is to appoint your new accountant before informing the old one. Your new firm will issue a professional clearance letter to the outgoing accountant — a standard industry procedure that requests a handover of records, outstanding filing positions, and any work in progress. The outgoing accountant is professionally obliged to respond under AAT and ACCA codes. They cannot withhold information you are entitled to.

What you should request from your old accountant: signed copies of your last three years of filed accounts and CT600s, your HMRC agent authorisation reference, your Companies House authentication code if they hold it, and a written confirmation of any outstanding deadlines. Do not assume this will happen automatically — request it explicitly in writing.

Timing matters. Do not switch during the month before a filing deadline. If your accounts are due in September and you switch in August, the handover period may create a gap. The ideal window is immediately after a filing completes, or at least three months before the next one. Your new accountant needs time to review records, draft accounts, and file under their own firm reference.

HMRC agent authority transfer: your new accountant submits a new 64-8 authorisation form online. This takes up to 10 working days to process. During that window your old accountant remains technically authorised, which is another reason to switch cleanly rather than abruptly. Companies House access is separate — your new firm sets up their own WebFiling account linked to your company number.

If your current accountant is not registered as an ACSP, they cannot verify your identity for Companies House. You can still verify directly through GOV.UK One Login, or use an authorised agent such as Fileminder if you prefer guided support.