"Business name", "company name", "trade mark", "domain name", these sound similar but mean different things in law, and confusing them is a common and costly mistake. Here is a plain-English guide for England and Wales.
Four different things
- Company name, the official, registered name of a limited company at Companies House. Every company must have one; it must be unique, follow naming rules, and usually end in "Limited"/"Ltd" (or "plc").
- Business (trading) name, a name a business trades under that is different from its official name (e.g. "Smith Plumbing" used by Smith Plumbing Ltd, or any name a sole trader uses). It is not separately registered at Companies House.
- Trade mark, a registered right (at the UK Intellectual Property Office) protecting a brand name or logo for particular goods/services, giving you the right to stop others using a confusingly similar mark.
- Domain name, your website address, registered with a domain registrar; first-come, first-served, and separate from the others.
Is it necessary to have a business name?
- A limited company must have a registered company name.
- A sole trader or partnership does not have to register a separate business name, and can simply trade under the owners' names, but most choose a trading name for branding.
So a trading name is optional, but you must follow the rules if you use one.
Rules you must follow
Whatever name you trade under:
- Avoid clashes, don't choose a name that is the same as, or too similar to, an existing company name or someone's registered trade mark, or you risk an objection or infringement claim.
- Restricted/sensitive words, certain words (e.g. "Royal", "Bank", "Institute") need permission; offensive names are not allowed.
- No misleading impressions, e.g. don't imply you are a PLC or government body when you are not.
- Trading disclosures, obligations differ by legal form: a company trading under a different brand must comply with company trading-disclosure rules (including its registered company name and other prescribed particulars on business documents and websites, under the Companies (Trading Disclosures) Regulations 2008); sole traders and partnerships using a business name must comply with the business-name disclosure rules under Part 41 of the Companies Act 2006.
Protecting your name
A business/trading name does not by itself give you exclusive rights. To protect a brand and stop copycats, register a trade mark. Securing the matching domain and social handles is also wise.
How to change a business name
- Company name: change it by special resolution of the shareholders (or by another method allowed in the articles), then file the change with Companies House (which issues a new certificate of incorporation on change of name). Update stationery, bank, contracts and HMRC.
- Trading name: you can usually change a sole trader's/partnership's trading name freely (no central registry), but update your disclosures, marketing and customers, and re-check for clashes and trade-mark issues.
- Trade mark: a registered mark is tied to the mark as registered, a new brand may need a new application.
Key takeaways
- Distinguish company name (registered at Companies House), trading name (what you trade under), trade mark (registered brand protection), and domain (web address).
- A company must have a registered name; a trading name is optional but must follow the rules and trading-disclosure requirements.
- A name alone gives no exclusive rights, register a trade mark to protect a brand.
- Change a company name by special resolution + Companies House filing; a trading name can usually be changed freely (re-check clashes and update disclosures).
Sources
- Companies Act 2006, Part 5 (company names; restricted/sensitive words; change of company name by special resolution); Part 41 (business-name disclosure rules for sole traders, partnerships and others); Companies (Trading Disclosures) Regulations 2008 (company trading-disclosure requirements)
- Trade Marks Act 1994 (registered trade mark protection via the UK Intellectual Property Office)
- General law on passing off (protecting unregistered goodwill in a name)
--- This article is general information about the law of England & Wales as at 2026, not legal advice. For advice on your circumstances, consult a qualified solicitor.