A UK company name must be unique on Companies House, must not be "too like" an existing name, must include "Limited" or "Ltd" for private companies, and must not contain prohibited words without permission. Before settling on a name, also check trademark availability, domain availability, and whether the name will work as your brand at scale.

Most UK founders pick a company name in 30 minutes and regret it within 18 months. The legal checks take 10 minutes. The brand checks deserve longer.

The Companies House rules

A UK company name must:

End with "Limited" or "Ltd" (or "Cyfyngedig" / "Cyf" in Welsh) for a private company limited by shares.
End with "Public Limited Company" or "Plc" for a public company.
Not be identical to a name already on the register.
Not be "too similar" to an existing name. This is judged by Companies House. Variations like spacing, hyphens, or "the" do not count as different.
Not contain "sensitive" words without permission (Royal, Bank, Chartered, Solicitor, Institute, Federation, and many others).
Not be offensive.
Not imply a connection to government or local authority without permission.

Check availability on the Companies House WebFiling search. If your chosen name is available there, you can proceed with incorporation immediately. Fees apply for some sensitive words.

Trademark vs company name (the common confusion)

A registered company name is not a trademark. The two are separate systems.

Companies House registers the legal name of the entity. Trademark registration (through the UK Intellectual Property Office) protects the brand name for specific goods and services.

You can incorporate "Smith Coffee Ltd" at Companies House and still face a trademark infringement claim from "Smith Coffee" the established cafe chain that registered the trademark first.

Before settling on a name, search:

UK trademark register (IPO online search).
EU trademark register if you'll trade in the EU.
US trademark register if you'll trade in the US.
Common law usage: a Google search for "[name] limited" or "[name] [industry]" turns up existing businesses using the name even without registered trademarks.

A name available at Companies House but already trademarked elsewhere is a trap.

Domain availability

The .com or .co.uk domain matters for credibility. Check:

Exact match: yourcompanyname.co.uk and .com.
Common variations: with and without hyphens, common misspellings.
Social media handles: Twitter/X, Instagram, LinkedIn.

If the .com is owned by someone else and not available, consider whether you'll always have to add a qualifier ("trythiscoffee.co.uk", "smithcoffee.uk"). Most growing brands eventually buy their .com from the existing owner; expect to pay £500 to £50,000 for a moderate-quality domain.

If you can't get any decent domain, pick a different name. Domain availability is a constraint, not an afterthought.

Picking a name that scales

Beyond legal availability, consider:

Pronouncable. If people stumble over it, they remember it less. Test by saying it on the phone to three people. Did they get it right?

Spellable. When someone hears your name, can they spell it correctly when searching? "Verity Partners" works. "Vyrity Partners" doesn't.

Memorable. Generic names blend in. Distinctive names stand out. "Brilliant Marketing Solutions Ltd" is forgettable. "Rajoka" is not.

Not too narrow. If your name describes your current offering specifically, you'll outgrow it. "Birmingham Bookkeeping Ltd" struggles when you expand to Manchester or to wider accounting services.

Works internationally. Names that mean something innocuous in English can mean something inappropriate elsewhere. Search the proposed name in major languages.

The "too like" trap

Companies House routinely rejects names that are too similar to existing companies. The rules:

Punctuation differences don't count (Smith Co. = Smith Co).
Common spelling variations are treated as the same name.
Plurals are typically the same as singulars.
Numbers may or may not count as differentiators (Smith 1 vs Smith 2 is allowed; Smith vs Smith Limited is not).

If you incorporate a name that's later challenged as too similar by an existing company, Companies House can order you to change it. Painful and expensive.

If in doubt, file a free name availability check or pay for a Companies House same-day check before committing.

Sensitive words and approvals

The Company, Limited Liability Partnership and Business (Sensitive Words and Expressions) Regulations 2014 list words that need approval. Examples:

British, English, Welsh, Scottish, Irish, National: require explanation of why these terms apply.
Charity, Foundation, Institute, Federation: require evidence of genuine connection.
Bank, Insurance, Financial: require FCA permission (or evidence you're not regulated).
Royal, Crown, Her/His Majesty: require Royal approval.
University, College, Academy: education-related approvals.

Including any of these in the name without permission means rejection. Worth checking the official list before getting attached to a name.

What if the name is already taken

Common situation. A company already has the name you want. Options:

Pick a different name. Usually the right answer.
Buy the name. If the holder company is dormant or not trading actively, you can sometimes acquire it. Cost varies wildly.
Add a qualifier. "Smith Bookkeeping Solutions" if "Smith Bookkeeping" is taken.
Wait for it to lapse. Dissolved company names become available 20 years after dissolution. Not a practical strategy.
Use a different word. Look for a name that captures the same brand idea differently.

Bottom line

Pick the name in this order: trademark check first, Companies House check second, domain check third, brand fit check fourth. Most founders do these in reverse, which is why so many UK companies eventually rebrand.

Choosing a business name in the UK: rules and checks