How do I close an HMRC enquiry?

An HMRC enquiry doesn't end just because correspondence stops, or because you feel you've answered everything HMRC could reasonably ask. It formally ends only when HMRC issues a closure notice, a document that states either that no amendment is needed, or exactly what amendment HMRC is making and why.

In practice, most enquiries close through negotiation: you and HMRC reach an agreed position on the facts and figures, and HMRC then issues a closure notice reflecting that agreement. If you disagree with HMRC's conclusions, you can still ask for a closure notice reflecting HMRC's position, then appeal it.

If HMRC seems to be taking an unreasonably long time without progressing matters or explaining why, the law gives you a way to force the issue: applying to the First-tier Tribunal for a direction that HMRC issue a closure notice within a specified period.

Section 28A Taxes Management Act 1970 governs closure of Self Assessment enquiries, with equivalent provisions for Corporation Tax under the Finance Act 1998 enquiry regime. Both require HMRC to issue a formal closure notice rather than simply letting matters lapse.

Where multiple issues are under enquiry, HMRC can sometimes issue a partial closure notice dealing with one specific matter while the enquiry remains open on others, allowing resolved points to be settled and appealed without waiting for everything to conclude.

The tribunal application route exists precisely because enquiries can otherwise run indefinitely. The tribunal will consider whether HMRC has reasonable grounds for keeping the enquiry open and can order a closure notice within a set timeframe if it isn't satisfied.

A long-running enquiry into company or personal tax affairs can create real uncertainty for business planning, financing and even sale negotiations, since an open enquiry is often a disclosure item that needs explaining to lenders or buyers.

Where you believe HMRC has all the information it needs and simply hasn't progressed the case, it's worth first asking HMRC directly for a timeline or an update, since a tribunal application is a formal step best used once informal attempts haven't worked.

If the enquiry covers several tax years or several issues, discuss with your accountant whether a partial closure notice could resolve the settled points now, so at least part of the uncertainty is removed while other matters are worked through.

The main cost of a stalled enquiry is time and ongoing uncertainty, plus interest continuing to accrue on any eventual liability throughout the period the enquiry stays open.

Applying to the tribunal for a closure direction has its own procedural costs and requires a properly prepared application, so it's usually a step taken with professional support rather than alone.

Growth plan clients have free tax investigation insurance included, which covers professional fees for managing the enquiry through to closure, including preparing a tribunal application if needed — see /fees for what's covered.

Don't assume silence from HMRC means the enquiry has quietly ended. Nothing is resolved until a closure notice arrives, and the enquiry remains legally open until then.

Don't rush into a tribunal application without first trying to get HMRC to engage or explain the delay. Tribunals expect to see that reasonable informal steps were tried first.

Don't miss the 30-day appeal window once a closure notice does arrive. Receiving it is not the end of your options if you disagree, but you must act promptly.