UK Company Name Rules 2026: What You Can & Cannot Use

Choosing the right name for your UK company is the first decision you make when forming, and getting it wrong wastes time and money. Beyond simply checking that the name is not taken, UK law sets out a range of rules — prohibited words, sensitive expressions requiring approval, and restrictions that protect trademarks and the public. This guide covers everything you need to know before you register, and sits alongside the full UK Company Name Rules 2026 reference.

Basic Name Rules

All UK private limited companies must follow these foundational rules for their registered name:

• Must end with "Limited" or "Ltd" — this is a legal requirement for private limited companies. "PLC" is used only by public limited companies.
• Must not be identical to another registered name — Companies House will reject names that are the same as, or too similar to, an existing name on the register.
• Must not contain certain characters at the start — names cannot begin with certain symbols or characters that could cause technical issues on the register.
• Must be in permitted characters — letters, numbers, and certain punctuation marks are permitted. Full rules are in the Company, Limited Liability Partnership and Business Names (Miscellaneous Provisions) Regulations 2009.

Welsh companies may use "Cyfyngedig" or "Cyf" instead of "Limited" or "Ltd", and must have a registered office in Wales.

Checking Availability

Use the Companies House name availability checker to search the register. Be aware that Companies House treats certain variations as the same name:

• Punctuation differences: "Smith-Jones Ltd" and "SmithJones Ltd" may be considered the same
• Common words: "The", "A", "An" at the beginning are ignored for comparison purposes
• Abbreviations: "&" and "and", "Ltd" and "Limited", "Co" and "Company" are treated as equivalent
• Plural/possessive: "Smith's" and "Smiths" may be treated as the same

Even if a name passes the automated check, Companies House may object manually if the name is too similar to an existing business of the same type.

Sensitive Words Requiring Approval

Some words may only be used in a company name with prior written approval from Companies House or the relevant body. Examples include:

Word/Expression	Approval needed from
Bank, Banking, Banker	Prudential Regulation Authority (PRA)
Insurance, Assurance, Reinsurance	Financial Conduct Authority (FCA)
Royal, King, Queen, Prince, Princess	Cabinet Office
British, National, England, Scotland, Wales	Companies House consideration
University, Institute of Technology	Department for Education / Privy Council
Charity, Charitable	Charity Commission
Trust	Financial Conduct Authority (if financial services)
Group	Companies House (must demonstrate it is a group)

The full list is set out in the Company, Limited Liability Partnership and Business Names (Sensitive Words and Expressions) Regulations 2014. If you want to use a sensitive word, submit your application with the required supporting letter to Companies House before or alongside your incorporation application.

Prohibited Names

Certain names are never permitted regardless of approval:

• Names that contain offensive words or expressions
• Names that suggest a criminal purpose
• Names that imply a connection to a government department or local authority without authority
• Names that would constitute a criminal offence to use

Companies House has discretion to reject any name it considers likely to mislead the public or damage the reputation of the register.

Company Name vs Trading Name

Your registered company name is the legal name on the Companies House register — it must appear on all official documents, letterheads, invoices, contracts and your website.

A trading name (also called a business name) is a name under which you trade that is different from your registered name. For example, your company might be registered as "Zhang Wei Consulting Limited" but trade as "Clearview Analytics". This is perfectly legal — you do not need to register the trading name at Companies House.

Trading name rules:

• Cannot include any of the prohibited words
• Cannot be the same as a registered trademark you do not own
• You must still display the registered company name and number on all official documents
• You can register a trading name as a trademark at the UK Intellectual Property Office to protect it

Trademarks: A Separate Check

Companies House only checks the company name register — it does not check trademarks. A company name that clears the Companies House check could still infringe a registered trademark, exposing you to trademark infringement claims and potentially forcing a costly name change later.

Before finalising your company name, search the UK Intellectual Property Office trademark register. Pay particular attention to class(es) relevant to your industry. If the name is clear, consider registering it as a trademark yourself to protect it — a UK trademark registration costs £170 for one class (online).

How to Change a Company Name

If you need to change your company name after incorporation:

1. Pass a special resolution of the shareholders (75%+ majority), or an ordinary resolution if your Articles of Association allow name changes by ordinary resolution.
2. File form NM01 at Companies House with a copy of the resolution and the £20 filing fee (online).
3. Companies House processes the change and issues a new certificate of incorporation on change of name — usually within 24–48 hours when filed online.
4. Update your registered office, bank accounts, contracts, website, letterheads, and HMRC records.

There is no limit on how many times a company can change its name. The company retains its original company registration number — it is the same legal entity regardless of name changes.

Frequently Asked Questions