UTRs, VRNs and company numbers: which identifier goes where

UK business identifiers overlap confusingly, and mixing them up causes real filing delays. Here is the short version.

A Unique Taxpayer Reference (UTR) is ten digits, issued by HMRC when a business or individual registers for Self Assessment or corporation tax. It identifies the taxpayer to HMRC — it does nothing at Companies House.

A VAT registration number (VRN) is nine digits, sometimes shown with GB prefix. Only businesses registered for VAT have one; turnover above £90,000 makes registration compulsory.

A company number is seven digits (or two letters plus six), issued by Companies House at incorporation. It identifies the company to the registrar, not to HMRC.

A National Insurance number belongs to a person, never a business. It has no place on a company record except for sole traders, where the person is the business.

In AVERQIS each of these lives in its own validated field — UTRs are checked for length and format on entry — because an identifier in the wrong column is worse than a missing one.