Company Name Checker

UK Companies House applies four broad rules to company names: they must be unique on the register, they must not be 'too similar' to an existing name, they must not contain restricted words without prior approval, and they must end with the correct suffix for the company type (Ltd, Limited, PLC, LLP, etc). The checker runs your proposed name against these structural rules before you submit, catching most issues that would cause a rejection.

Restricted words include 'Royal', 'Crown', 'Government', 'NHS', 'Police', 'University', 'Bank', 'Charity', 'Trust', and 'Authority' among others. Using these requires written permission from the relevant body, and Companies House will reject names containing them without proof of approval. Even cleared names like 'British' or 'National' often need supporting justification if they appear too official or quasi-governmental.

Companies House uses a same-as test that ignores common word variations. 'Acme Ltd' and 'Acme Limited' are considered identical. 'Acme UK Ltd' and 'Acme Ltd' are considered too similar (the geographic descriptor doesn't differentiate enough). 'Acme Holdings Ltd' and 'Acme Ltd' are usually considered different because 'Holdings' is a substantive descriptor. The line is fuzzy and ultimately decided by Companies House staff during the application review.

If a name is rejected as too similar to an existing company, you have to choose a different name. There is no appeal mechanism beyond providing evidence that the existing company has explicitly consented to your use of a similar name (which they almost never will). Save yourself the rejected application by checking the live Companies House register at find-and-update.company-information.service.gov.uk before submitting.

A name passing Companies House checks does not mean the name is yours to use freely. A registered trade mark in your sector blocks your right to trade under that name even if Companies House accepts the registration. The UK IPO trade mark database at ipo.gov.uk should be checked before committing to a name, especially in classes 9, 35, 38, 41 and 42 which cover most modern services.

Domain availability is a third concern. The .co.uk and .com versions of your chosen name are rarely both free; if both are taken, your marketing options are constrained from day one. Check at a registrar such as Nominet (.uk) or your preferred provider before settling. The [business-name-generator](/business-name-generator) can help if you need fresh ideas after a rejection. This is a basic naming check; always verify final availability on Companies House before registering.