The trade mark letter that arrived five years in

It is a specific kind of sick feeling. The envelope is from a firm of solicitors, the tone is polite, and the substance is that the name above your door belongs to somebody else. They have had it registered for years. They would like you to stop using it, hand over the domain, and confirm in writing within fourteen days that you have done so.

The instinctive reaction is that this cannot be right. You registered the company at Companies House. You have traded under the name for five years. You have invoices, a website, a Google listing, signage, a van. Surely five years of use counts for something.

It counts for less than almost every owner assumes, and the gap between what people think a business name gives them and what it actually gives them is one of the more expensive misunderstandings in small business.

Registering a company is not registering a name

Companies House does one thing: it stops another company being incorporated with a name that is the same as, or very close to, an existing registered company name. That is a records function. It confers no right to use the name in trade, and it gives you no ability to stop anyone else using it.

The register is not even checked against the trade mark register. You can be granted a company name that infringes an existing trade mark on the day you incorporate, and Companies House will not mention it. Buying the domain adds nothing either.

What actually creates a monopoly in a name is registration at the Intellectual Property Office, for specified goods and services, in specified classes. That right is national, it lasts ten years, it is renewable indefinitely, and the UK operates broadly on a first-to-file basis. The person who filed first generally wins, whether or not they were trading first.

The one right you do have, and its limits

There is a common-law remedy called passing off, and it is what unregistered users fall back on. To succeed you must show goodwill in the name, a misrepresentation by the other party, and damage. It is real, it works, and it is worth knowing about.

It is also slow, evidence-heavy and expensive. Proving goodwill means assembling years of trading evidence and often survey material. It is a High Court remedy, not a form you file. Compared with a registered mark — where infringement can turn simply on whether the marks and the goods are identical or confusingly similar — it is a far harder and costlier route.

There is also honest concurrent use, where two businesses have genuinely coexisted under similar names for years without confusion. It occasionally survives a challenge. It is a defence to argue over, not a plan to rely on.

Companies House told you the name was available. That is a filing clerk's answer to a filing clerk's question — it was never a statement that the name was yours.

What the letter actually costs to resolve

The registration side is cheap, which is what makes the whole story so annoying in retrospect. Applying online at the IPO costs £205 for one class and £60 for each additional class, with those fees applying from 1 April 2026 — the first increase since 1998. Renewal is £245 a decade later. A basic clearance search of the register is free to do yourself.

The dispute side is not cheap. Opposing an application costs £125 or £250 depending on the grounds, before anyone's time. Responding properly to a letter before action means a solicitor reading the registration, checking the classes, checking the specification, and checking whether the mark has actually been used in the last five years — because a registration unused for five years can be vulnerable to revocation, which is sometimes the strongest card an accused infringer holds.

And the rebrand side, if it comes to that, is where the real money goes: signage, vehicle livery, workwear, printed materials, packaging, a new domain, redirects, re-optimising a website that ranked for the old name, updating every directory and marketplace listing, and telling a customer base who know you by something else. For a small business with a van and a shopfront that is a five-figure exercise and months of drag, and none of it grows the business by a penny.

What to do if the letter arrives

Do not reply on the day, and do not reply yourself. Anything you write is evidence, and an email admitting you knew about them is worth more to them than the letter is.

Do not immediately take everything down either, because you may have more ground than you think and you have just handed them the outcome for free.

Get the registration number from the letter and look it up on the IPO register. Check three things: what the mark actually is, which classes and which goods and services it covers, and when it was registered. A mark registered for software does not automatically reach a plumbing business. The scope is often much narrower than the letter implies.

Then take an hour of specialist advice before you do anything else. Trade mark work is a distinct discipline and this is not the moment for a general commercial solicitor. Ask specifically about non-use revocation, about the actual overlap of classes, and about whether coexistence — a written agreement that you each stay in your lane — is achievable, because in practice a negotiated coexistence agreement resolves more of these than a court ever does.

The version where this never happens

Before you commit to a name — before the signage, before the livery, before five years of goodwill — spend twenty minutes searching the IPO register for the name and anything close to it in the classes you will trade in. It is free.

Then file. Two hundred and five pounds against the cost of a forced rebrand is not a close call, and it is the single cheapest piece of legal protection a small business can buy. There is a two-month window in which others can oppose your application, and if it goes through unopposed you have a registered right you can actually enforce.

It is the same shape as the contract clause worth adding to every quote and the GDPR job that gets put off for two years: a small, boring, cheap job that stays worthless right up until the day it is the only thing standing between you and a very expensive month.

Common questions

Do I own my business name if it is registered at Companies House?

No. Companies House registration only prevents another company being incorporated with the same or a very similar name. It gives you no right to use the name in trade and no ability to stop anyone else using it, and the register is not checked against the trade mark register — so you can be granted a company name that infringes an existing registered mark without anyone flagging it. Owning the domain adds nothing legally either. The only way to obtain an enforceable monopoly in a name is to register it as a trade mark at the Intellectual Property Office, for specific goods and services in specific classes.

How much does it cost to register a UK trade mark?

Applying online through the Intellectual Property Office costs £205 for the first class of goods or services and £60 for each additional class, with those fees in force from 1 April 2026 — the first increase in UK trade mark fees since 1998. Paper applications cost more. Registration lasts ten years and renewal online is £245 plus £60 for each extra class. Searching the register beforehand to check nobody holds a conflicting mark is free. Against the cost of a forced rebrand — signage, livery, packaging, domain, redirects and the lost search rankings — it is the cheapest legal protection a small business can buy.

What should I do if I receive a trade mark infringement letter?

Do not reply the same day and do not reply yourself, because anything you write becomes evidence. Do not take everything down immediately either — you may have more ground than the letter suggests. Take the registration number from the letter, look it up on the IPO register, and check what the mark actually is, which classes and goods it covers, and when it was registered; the scope is frequently narrower than claimed. Then get an hour with a trade mark specialist rather than a general commercial solicitor, and ask specifically about non-use revocation, genuine class overlap, and whether a coexistence agreement is achievable.

Can I keep using a name I have traded under for years?

Sometimes, but it is a harder and more expensive argument than most owners expect. Unregistered users rely on passing off, which requires proving goodwill in the name, a misrepresentation and resulting damage — a High Court remedy that is slow and evidence-heavy compared with enforcing a registered mark. There is also honest concurrent use, where two businesses have genuinely coexisted without confusion for a long period, but that is a defence to argue rather than a plan to rely on. One stronger card is non-use: a registered mark that has not genuinely been used for five years can be vulnerable to revocation.