Email signature legal requirements in the EU

What does EU law require?

Article 26 of the directive says member states must require that letters and order forms, whether on paper or in any other medium, state:

• the register where the company is filed and its registration number,
• the company's legal form and the location of its registered office,
• where relevant, that the company is being wound up.

If the capital is mentioned, it must be the subscribed and paid-up capital. The same details must appear on the company website.

Does it apply to email?

Yes, in practice. The directive explicitly covers "any other medium", and business email that a company sends to customers, suppliers and partners (quotes, replies, orders) is treated as a business letter in most member states.

National examples

• Slovenia (Article 45 of the Companies Act, ZGD-1): full company name, registered office, registry court and registration number; for limited and joint-stock companies also the share capital and any unpaid contributions.
• Germany (for a GmbH, §35a GmbHG): legal form, registered office, registry court and register number, plus all managing directors and, if there is one, the chair of the supervisory board.
• Other countries have similar lists. Check your own company law before you finalize the footer.

Example signature with the required details

Keep the personal part short and put the legal details in a smaller footer below it:

What is not required?

• VAT number: required on invoices, not on every email in most countries. Many companies add it anyway.
• Confidentiality disclaimers are not legally required and usually have little legal effect. If you want one, keep it short.
• Bank details are not required in a signature.
• Logo, social links and banners are about the brand, not the law.

How to make sure everyone has it

If each employee sets up their own signature, some will miss the footer or keep an old version after the capital or office changes. Put the footer in a central template instead:

• in Microsoft 365, with a signature tool or an Exchange Online rule that appends text to messages,
• in Google Workspace, with the footer in the Admin console (Google Workspace email footer vs. signature) or through the Gmail API,
• in SignetMail, as part of the template: change it once and every signature follows.

Checklist

• Is the full legal name shown, with the legal form?
• Are the registered office and the register shown?
• Is the registration number shown?
• If capital is mentioned, is it the subscribed and paid-up amount?
• Do national rules ask for more, such as the names of directors?
• Is the footer the same for every employee, in Outlook and Gmail on phones too?

Frequently asked questions

Is an email legally a business letter?

The EU directive covers letters in any medium, and member states generally treat external business email as business correspondence. Internal email usually doesn't need the legal footer.

Do I have to state the share capital?

Under EU law, only if you mention capital at all, and then it must be the subscribed and paid-up amount. Some countries, such as Slovenia for limited companies, require it on every letter.

What about sole traders?

The directive covers limited liability companies. Sole traders follow national rules, which are often lighter; check with your accountant.