Email signature generator › UK company details

What a UK company must show in business email

A registered company in the United Kingdom has to carry particular details on its business correspondence, and email counts. The list is short and specific, which makes it easy to comply with once you know it.

The four particulars

A company registered in the United Kingdom must state, on its business letters, order forms and websites — and business email is treated as correspondence for this purpose:

1. The full registered company name, exactly as registered, including the Limited or Ltd suffix.
2. The registered number.
3. The part of the United Kingdom in which it is registered — England and Wales, Scotland, or Northern Ireland.
4. The address of the registered office.

These come from the Companies Act and the associated trading disclosures regulations. The requirement is on the company, and it applies to correspondence sent by anyone on the company's behalf.

The trading name case

If the company trades under a name different from its registered name, the registered name must still appear. A signature showing only the trading name does not comply, however well known the trading name is. The usual form is the trading name in the visible part of the signature and the registered name in the small print below.

Sole traders and partnerships

An unincorporated sole trader is not a registered company and the company particulars do not apply. There is a separate and lighter requirement: if you trade under a name that is not your own, the business documents must show your own name and an address at which documents can be served.

So a freelancer working under their own name has nothing to add. A freelancer trading as a studio name does need to show who is behind it.

VAT registration

Being VAT registered does not by itself require the number in your email signature — the obligation attaches to invoices. Many businesses include it anyway because it saves a question from new clients, which is a practical reason rather than a legal one.

Making it small

Four particulars written out take about two lines at a small size. They are required on every message, so they should carry no images and no styling beyond a reduced font size and a lighter grey. A compliant block can be well under 300 bytes, which is small enough to repeat down a long thread without consequence.

Put it last. It is required, not useful to the reader, and everything above it gets read first.

The caveat

This describes the general requirement as it is commonly understood. Whether and how it applies to your particular arrangement — a branch of an overseas company, an LLP, a charity — is a question for whoever advises you. The list above is what to check against, not a substitute for asking.

What a compliant block looks like written out

Two lines at 11 pixels: the registered name with its suffix and the place of registration on one, the company number and registered office on the other. It comes to about 140 characters for a typical company, which is under 200 bytes — small enough that repeating it on every message in a long thread costs nothing measurable.

The website requirement is separate and often missed

The same particulars are required on the company's website, not only in correspondence. A business that has put them carefully into the email signature and left them off the site has solved half the problem. The usual place is the site footer or a legal notices page linked from it.

Overseas companies with a UK presence

A company registered outside the UK that has established a UK presence has its own disclosure obligations, which differ from those of a UK-registered company. If that describes your arrangement, the list on this page is not the right list, and the question is worth asking rather than assuming.

Frequently asked questions