What is a professional clearance letter?

What the clearance letter actually asks

Two things, in plain English. First, it asks the old firm whether there is any professional or ethical reason the new firm shouldn't act for you — for example, a concern the new firm should be aware of before taking the engagement on. Second, it asks for the practical bits of a handover: copies of your accounts, prior tax returns, trial balances, ledgers, payroll details, VAT records, and relevant correspondence with HMRC (ICAEW; ACCA).

That's the whole letter. It is short, polite, and written accountant-to-accountant. You don't see it, you don't draft it, and you don't sign it. Your role is simply to authorise your new accountant to send it.

What it is NOT — permission

This is the bit that confuses people, and it's the bit that matters most. You don't need your old accountant's blessing to switch. The relationship is yours to end. The word "clearance" refers to the new firm clearing that there's no ethical barrier to acting— it is not consent from the old one. Whether the old accountant likes it or not is irrelevant to your right to move.

If anyone has ever told you "your old accountant has to release you" or "you can't switch until they sign you off", they are wrong. You are not a hostage. You are a client choosing a different supplier, exactly as you would with any other professional service.

Who sends it — and when

Your new accountant sends the clearance letter, and they send it only after you've told them to proceed. In practice, the cleanest sequence is:

1. You tell your old accountant (a brief email is enough) that you're moving your affairs elsewhere.
2. You sign the new firm's engagement letter and complete the AML/ID check.
3. The new firm then sends the professional clearance letter to your old one.

That order matters for one reason: it means the old firm isn't blindsided. They receive the clearance letter from the new accountant after you've already given them notice, which keeps the conversation civil and avoids the awkward "you told them before you told us?" exchange.

The cooperation rule

Here's the protection that quietly underpins the whole process. If your old accountant belongs to a professional body — ICAEW, ACCA, IFA, AAT and others — they are bound by that body's code of ethics to respond cooperatively within a reasonable timeframe, barring genuinely exceptional circumstances. Stalling, ignoring the letter, or "forgetting" to send the records is not an option for a regulated firm.

That is why most switches go smoothly. Both firms are regulated by the same kind of professional body, both are bound by the same kind of code, and both treat clearance as the routine professional courtesy it actually is. A firm that drags its feet is putting its own regulatory standing at risk — not yours.

The step that sounds like it could go wrong — and almost never does

When clients hesitate to switch, they almost always picture this step. They imagine an awkward phone call, a refusal, or a request that gets ignored for months. In reality, professional clearance is the most automated, scripted part of the entire process. Two regulated firms exchanging a standard letter and a standard pack of records, on standard templates, under standard professional rules.

It is the step that sounds like it could go wrong, and it is the step that almost never does. And if it ever does — if your old firm genuinely stonewalls — that is a process issue with a clear escalation route, not a barrier to you leaving.

Where this fits in the switch

The clearance letter is one step inside a wider handover. For the full sequence — engagement letter, AML check, records request, HMRC agent re-authorisation and software handover — see The step-by-step process to change accountant. For what happens to your records, software access and cloud bookkeeping during the handover, see Your records, data and software — what happens to them.