Do I need to register my business name in the UK?

You can trade under your own name or a trading name without registering it anywhere. What you do need is to register with HMRC for Self Assessment once you earn more than £1,000 from self-employment in a tax year. HMRC records your business name, but that doesn't reserve it or give you any rights in it.

The business name rules are in Part 41 of the Companies Act 2006 and apply across the UK. A trading name must not:

• include "limited", "Ltd", "LLP", "plc" or other words suggesting a legal form you don't have (section 1197 of the Companies Act 2006)
• suggest a connection with the UK government, a devolved government, a local authority or certain public bodies without approval (section 1193 of the Companies Act 2006)
• use a sensitive word or expression, such as "Royal", "Chartered", "Charity", "Trust" or "University", without approval (section 1194 of the Companies Act 2006)
• be offensive, or be too similar to someone else's trade mark

Trading under a sensitive word without approval is a criminal offence. The full list of sensitive words is in the Companies House guidance on incorporation and names.

When you incorporate, the company's name goes on the Companies House index. There's no separate name registration, and Companies House doesn't let you reserve a name in advance. The main rules:

• it must usually end in "Limited" or "Ltd" ("Cyfyngedig" or "Cyf" for Welsh companies)
• it can't be the same as a name already on the index (section 66 of the Companies Act 2006). Names that differ only by punctuation, special characters or common words are usually treated as the same
• Companies House can direct a change if it's too like an existing name (section 67 of the Companies Act 2006)
• it can't be offensive, or a name whose use would be an offence (section 53 of the Companies Act 2006), and sensitive words need approval (section 55 of the Companies Act 2006)

A company can trade under a different name from its registered name. The business name rules for trading names apply to that name too.

If you're a sole trader or partnership using a name other than your own surname, you must show your name (or each partner's name) and an address where documents can be served on:

• business letters, orders, invoices and receipts, and written demands for payment (section 1202 of the Companies Act 2006)
• a notice at any premises your customers or suppliers visit (section 1204 of the Companies Act 2006)

Failing to do this is an offence, and it can stop you enforcing a contract in court if the other side lost out because of it (section 1206 of the Companies Act 2006).

A company must display its name at its registered office and other places it does business (not a home address). Its letters, order forms and website must show its full registered name, registered number, registered office address and where it's registered: England and Wales, Scotland or Northern Ireland.

Neither HMRC nor Companies House checks the trade mark register. A company name only stops another company registering the same name. It doesn't let you stop others trading under a similar name, and it won't protect you if someone already owns a trade mark for it. They could make you rebrand, even if Companies House accepted your name.

Before you commit, search the Intellectual Property Office trade mark register, the Companies House register and the web. To protect the name as a brand, apply to register it as a trade mark. An online application costs £205 for one class of goods or services, plus £60 for each extra class.