A professional email signature for a UK business needs your name, role, company, one phone number and one link, and for a limited company a short legal line with the registered name, company number, place of registration and registered office. Keep it as text with one small logo, build it once, and paste it into Gmail, Outlook and your phone so every message carries the same details.
An email signature appears on almost every message a small company sends, often to the people most likely to buy, and it is usually put together in five minutes and never looked at again. It is also, for a limited company, a legal document. This guide covers what the law requires, what to leave out, a layout that holds up in Outlook, and a way to build the signature once and hand it to the whole team. Checked on 19 October 2026.
What the law requires
The rules come from the Companies Act 2006 and the Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015, which replaced the 2008 regulations. They work in two layers.
- A company must show its registered name on all forms of its business correspondence, which includes email (regulation 24).
- On business letters, order forms and websites it must also show the part of the UK it's registered in, its registered number and its registered office address (regulation 25).
Business emails to customers and suppliers are generally treated as business letters, so the simplest way to stay on the right side of both rules is to put all four details in the signature everyone uses. The disclosures must be readable with the naked eye, so put them in text, not only in a logo. A company that fails to comply without reasonable excuse, and its officers in default, can be fined (regulation 28). LLPs have similar rules with their own wording for members.
GOV.UK's guide to signs, stationery and promotional material adds two points. If you mention share capital, you must say how much is paid up. And if a letter names any director other than in the text or as the person signing, it must name every director, so signing off as "Jo Bloggs, Managing Director" doesn't on its own mean listing the whole board.
A VAT number isn't one of the required email details, though it's required on VAT invoices. Sole traders and partnerships aren't covered by the company rules, but if they trade under a business name rather than their own names, the Companies Act requires them to show the owners' names and an address for service on business letters and certain other documents.
The legal line goes at the bottom in small, readable text, in one or two lines. Something like "Nook Coffee Ltd, registered in England and Wales, company number 12345678. Registered office 1 Example Street, Leeds LS1 1AA." is complete. The company and address are fictional.
What to include, in order
- Your name, then your role.
- The company name as text, with a small logo beside it if you like.
- One phone number.
- One link. A bio link page is ideal here because it holds the website, the booking page, the social accounts and a vCard behind a single address, so the signature stays short.
- The legal line.
Five lines plus the legal line is enough. Everything else competes with the message you actually wrote.
What to leave out
- Inspirational quotes and taglines.
- A row of six social icons. One link to a page that lists them does the same job and works in every email client.
- Large images, banners and scanned handwritten signatures. Many clients block images by default, and the reader sees a broken box.
- Long confidentiality disclaimers. They make the signature longer and push the legal line off a phone screen. If your sector or compliance team expects one, use their wording and keep it short.
- "Sent from my phone" apologies. Set up the same signature on the phone instead.
A layout that survives Outlook and phones
- Use text, not a picture. A signature saved as one image cannot be copied, searched or read by screen readers, and it is blocked by default in many inboxes.
- Keep it compact. Something around 300 to 400 pixels wide usually reads well on a phone, but test it at mobile width rather than trusting a number.
- Use web-safe fonts. Arial, Helvetica, Georgia or Verdana. A brand font that is not installed on the reader's device is replaced by something you did not choose.
- Add one small logo with alt text, optimised so it loads quickly, on a transparent background so it works in dark mode. The image optimiser gets it there.
- Check dark mode. Avoid pure white text and pure black backgrounds in the signature itself; let the email client set them.
- Don't attach the logo. A logo added as an attachment appears as a file on every email you send.
Build it once with the signature builder
The Email Signatures section of the Digily Link dashboard builds the signature from a template. Choose Plain text or one of the designed templates, fill in the name, job title, company, phone number, website, address, social accounts and an optional disclaimer line, add a logo by image address, then copy the signature or its HTML code. Use Copy signature for visual editors like Gmail's, and the HTML code only where your email app accepts HTML source. The free plan includes five signatures, Starter 25 and Pro 50, which is enough to give each member of a team their own version of the same design.
In Gmail on a computer, go to Settings, See all settings, then the Signature section, choose it as the default for new emails and replies, and click Save Changes. Gmail allows up to 10,000 characters, and images count towards that. In new Outlook and Outlook on the web it's Settings, Accounts, then Signatures, while classic Outlook for Windows has its own Signatures window. The Gmail and Outlook phone apps have separate signature settings, and they don't always show the same formatting, so send yourself a test from each. Steps from Gmail Help and Microsoft Support.
One thing to avoid mixing up. Our free online signature generator is a drawing pad for a handwritten signature, which you can download as an image. It's useful for signing documents, but as explained above, a handwritten signature image shouldn't replace a text signature with your details.
Measure the link
A signature link is a marketing channel, so treat it like one. Make the link a short link, for example digily.uk/yourname, so it can be changed later without asking the whole team to update their signatures, and tag its destination with the UTM link generator using utm_source=signature and utm_medium=email. The statistics then show how many times the signature link is opened.
If you meet people in person as well, a vCard QR code in the signature is worth considering, as described in the guide to vCard QR codes for business cards. Keep it small and remember that images may be blocked, so the text link must stand on its own.
If you tag the signature link, UTM parameters explained with a UK campaign example covers the naming rules, and branded short links on a .uk domain shows how to put the link on your own domain.
Frequently asked questions
Do sole traders need the legal line?
Not the company line. But a sole trader or partnership trading under a business name, rather than the owners' own names, must show the owners' names and an address for service on business letters, orders, invoices and receipts, under sections 1200 to 1202 of the Companies Act 2006.
Does it apply to internal emails and replies?
Internal emails, no. Replies to anyone outside the company, yes, because they are still business letters.
What about a Scottish or Northern Irish company?
Same rules, different wording. "Registered in Scotland" with the SC number, or "Registered in Northern Ireland" with the NI number.
Can the legal information be in a footer only on the first email?
No. Every business email needs it, which is why it belongs in the signature rather than typed by hand.
How do I give the whole team the same signature?
Build one design in the signature builder, duplicate it for each person with their name and number, and send each person their HTML. Changes to the company details are then a matter of updating the template and sending the new version once.
Final checks
- Registered name, number, place of registration and registered office are all present.
- The signature is text with one small logo, compact enough for a phone screen.
- There is one link, and it is a short link you can change later.
- It looks right in Gmail, Outlook and on a phone, in light and dark mode.
- Everyone in the company is using the same version.
