This is research, not legal advice. It reads the legislation for England and Wales, Scotland and Northern Ireland as it stood on 21 October 2026. For your own business, ask a solicitor, an accountant or your regulator.

Limited companies

The Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015 set out what a company has to show. Under regulation 24, every company must show its registered name on its business letters and on all other forms of its business correspondence and documentation, as well as on its websites.

Regulation 25 adds that its business letters, order forms and websites must give:

  • the part of the United Kingdom where it is registered, and its registered number;
  • the address of its registered office;
  • where it applies, that it is a limited company even though its name does not say so, or that it is an investment company.

If a company with a share capital mentions the amount, it must be the paid-up share capital. GOV.UK's guidance for limited companies gives the same list for business letters, order forms and websites: the registered number, the registered office address, where the company is registered, and the fact that it is a limited company, usually by using its full name with Limited or Ltd.

Why email counts

The regulations do not mention email by name, and they do not need to. Regulation 29 says that a reference to any type of document is a reference to a document of that type "in hard copy, electronic or any other form". A business letter sent by email is still a business letter, so a company's business emails need the same details as its letters.

Regulation 20 adds that the details must be in characters that can be read with the naked eye, so keep the line large enough to read.

Naming directors

A company does not have to name its directors on its emails. But under regulation 26, if a business letter includes the name of any director other than in the text or as a signatory, it must name every director. Signing your own email does not trigger it; a footer that names the managing director does.

Sole traders and partnerships

A sole trader or a partnership that trades under a business name, rather than the owners' own names, is covered by the Companies Act 2006 instead. Section 1202 requires the information in section 1201 on its business letters, written orders for goods or services, invoices and receipts, and written demands for payment. That information is:

  • the name of the individual, or of each partner;
  • for each person named, an address where any document about the business can be served, in the United Kingdom if the business has a place of business here.

Unlike the company regulations, the Act does not say in so many words whether an email counts as a business letter. The careful course is to treat it as one.

LLPs, charities and regulated firms

Limited liability partnerships, registered charities and firms regulated by a professional body have disclosure rules of their own, and a regulator may ask for a particular line on every email. Those rules are not covered here. Check with your regulator or adviser rather than copying another firm's footer.

Adding it to your signature

In Animated Signature, the registered name can be the company line, written in full with Limited or Ltd, and on the designs that print an address, the registered office can be that line. There is no field yet for a registered number or for the place of registration, so add those as text under the pasted signature, in your mail client's own signature box. One line is usually enough, in placeholders here so nobody copies a real company's details:

[Company name] Ltd. Registered in England and Wales, number [registered number]. Registered office: [registered office address].