UK email signature legal requirements

The short answer

The rules for business letters cover emails. The Trading Disclosures Regulations 2015 say that a reference to a type of document means that document “in hard copy, electronic or any other form” (regulation 29(c)). So a business email from a UK company or LLP must carry the same details as its letterhead.

Not required by these rules: a phone number, a VAT number or a confidentiality disclaimer. A minimal compliant footer for a limited company is four lines: the full registered name, “Registered in England and Wales” (or Scotland, or Northern Ireland), the company number and the registered office address.

Limited companies and PLCs

Section 82 of the Companies Act 2006 lets the government set the disclosure rules; the current ones are the Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015 (SI 2015/17). The company’s registered name must appear on its business letters, notices and other documents (regulation 24). Regulation 25(1) then requires, on business letters, order forms and websites:

“(a) the part of the United Kingdom in which the company is registered; (b) the company’s registered number; (c) the address of the company’s registered office.”

— SI 2015/17, regulation 25(1)

• Registered name: exactly as registered at Companies House, including “Ltd” or “Limited”, not only your trading name.
• Part of the UK: England and Wales, Wales, Scotland or Northern Ireland, for example “Registered in England and Wales”.
• Registered number: eight characters, for example 01234567 or SC123456.
• Registered office: the address on the public register, which may differ from your trading address.

Some companies must add a statement: a company exempt from using “limited” in its name, or a community interest company that isn’t a PLC, must say it is a limited company; an investment company must say so too (regulation 25(2)).

UK limited company (legal footer)

	Oliver Bennett Operations Director Hartley & Webb
T +44 161 496 0321 E oliver.bennett@hartleywebb.example W hartleywebb.example
Hartley & Webb Ltd · Registered in England and Wales · Registered number: 12345678 · Registered office: 18 Canal Street, Manchester M1 3EZ
Made with Fairsig

UK companies must show their registered name, number, place of registration and registered office on business email. The corporate template puts them in small print below the contact band.

Use this signatureCorporate template

Directors’ names: all or none

“Where a company’s business letter includes the name of any director of that company, other than in the text or as a signatory, the letter must disclose the name of every director of that company.”

— SI 2015/17, regulation 26(1)

You don’t have to name directors. Signing your own email is fine. But a footer that lists the managing director and the finance director while leaving out the other three breaks the rule.

Share capital: optional, but then paid-up

You never have to mention share capital. If you do, regulation 25(3) requires the paid-up share capital, not the authorised or issued amount.

LLPs

The same regulations apply to limited liability partnerships through the Limited Liability Partnerships (Application of Companies Act 2006) Regulations 2009 (SI 2009/1804, regulation 14). An LLP shows its registered name, part of the UK, number (for example OC123456 or SO301234) and registered office. And when its name ends in the abbreviation:

“in the case of an LLP whose name ends with the abbreviation ‘llp’, ‘LLP’, ‘pac’ or ‘PAC’, the fact that it is an LLP or a partneriaeth atebolrwydd cyfyngedig.”

— SI 2015/17, regulation 25(2)(d), as substituted for LLPs by SI 2009/1804

The “name one, name all” rule applies to members. An LLP with more than 20 members can instead keep a list of members at its principal place of business and state that address on the document.

Sole traders and partnerships with a business name

If you trade under your own surname, nothing changes. If you use a business name, Part 41 of the Companies Act 2006 applies (section 1200). Section 1201 asks for your name (or the name of every partner) and a UK address where documents can be served, and section 1202 requires them, in legible characters, on business letters, written orders, invoices, receipts and written demands for payment.

Part 41 doesn’t mention email, and the “electronic form” definition in the 2015 Regulations only covers companies and LLPs. Whether a sole trader’s email counts as a business letter is not settled in any official guidance we found. Adding your name and address costs one line, so it’s the cautious choice.

What about the VAT number?

HMRC requires your VAT registration number on VAT invoices (VAT Notice 700, section 16.3.1). None of the disclosure rules for business letters asks for it. Adding it to your signature is optional; the Fairsig generator offers it as an optional field.

What happens if details are missing?

• Companies and LLPs: failing to comply without reasonable excuse is an offence by the company and every officer in default, with a fine up to level 3 on the standard scale and a daily default fine (SI 2015/17, regulation 28).
• Sole traders and partnerships: section 1205 makes it an offence too (level 3 plus daily default fines), and under section 1206 a court can dismiss your claim under a contract if the other side lost out because the details were missing.

Since the Economic Crime and Corporate Transparency Act 2023, a company’s registered office must be an “appropriate address” and the company must have a registered email address. That email address is not public and doesn’t have to appear on your emails.

Make a compliant signature with Fairsig

1. Open the signature generator and expand Legal details in the Extras step.
2. Choose United Kingdom, then your company type (Limited, PLC or LLP).
3. Fill in the required fields (marked *): registered company name, registered number, place of registration and registered office. The generator checks the number format (8 digits, or 2 letters and 6 digits) and the VAT number if you add one.
4. The section heading shows how many details are still missing. When it says “complete”, every required field is filled in. For an LLP named “… LLP”, the generator adds “A limited liability partnership” for you.
5. Copy the signature and paste it into Outlook, Gmail or Apple Mail.

The check is a format check: the generator can’t know whether the number belongs to your company. Compare the details with your entry on the Companies House register.

Sole traders don’t need the legal section: put your own name in Name, your business name in Company, and your address in Address.

Design tips

• Put the disclosures at the very bottom, in smaller but readable text, never as an image.
• One detail per line, or separated by “·”: the generator does this for you.
• Use a shorter signature for internal emails and quick replies if you like, but keep the full version on emails to customers and suppliers.
• Long disclaimers aren’t required. They make the signature heavier and can push it past Gmail’s 10,000-character limit.

Sources

Legislation as published on legislation.gov.uk, read in October 2026:

• SI 2015/17, Part 6 (regulations 20–28: legibility, registered name, required details, directors, offences) and regulation 29 (electronic form)
• SI 2009/1804, regulation 14 (how the rules apply to LLPs)
• Companies Act 2006, section 82 and Part 41, chapter 2 (business names: ss. 1200–1206)
• GOV.UK: Running a limited company: signs, stationery and promotional material, VAT guide (Notice 700), Incorporation and names