Electronic signatures for businesses: legal, secure, and free to try

Electronic signatures are legally binding in the UK, EU, and US - and have been for over 20 years. You do not need DocuSign, Adobe Sign, or any other expensive platform to collect a valid signed document from a client.

This guide covers everything: what an electronic signature is, which laws make it enforceable, the difference between simple and qualified signatures, and how to send your first signature request in under five minutes.

What you will learn:

• What counts as an electronic signature (and what does not)
• Whether e-signatures hold up in court in the UK, EU, and US
• The three types of electronic signature and which one you need
• How NuDoc creates a tamper-evident signed PDF with a full audit trail
• Step-by-step: sending a signature request and getting it back signed

What is an electronic signature?

An electronic signature is any digital method a person uses to indicate they agree to the contents of a document. There is no requirement for a drawn or stylised signature. The law defines it by intent and evidence, not by appearance.

Under UK, EU, and US law, all of the following qualify as valid electronic signatures:

• Clicking a button labelled "I agree" or "Sign"
• Typing your full name into a designated signature field
• Drawing your signature on screen with a mouse, stylus, or finger
• Ticking a checkbox to accept terms

What makes an e-signature enforceable is not the method - it is the evidence attached to it. A reliable electronic signature system records who signed, when, from where, and that the document itself has not been altered since signing.

Are electronic signatures legally binding?

Yes. Here is the specific legislation in each major jurisdiction:

United Kingdom

The Electronic Communications Act 2000 established that electronic signatures are admissible as evidence and carry legal weight. UK eIDAS (retained from EU law post-Brexit) further reinforces this. For commercial contracts, service agreements, and business documents, a simple electronic signature is fully enforceable.

European Union

EU Regulation 910/2014 - known as eIDAS - created a unified legal framework for electronic signatures across all 27 member states. Simple Electronic Signatures (the type used by NuDoc) are valid for the vast majority of commercial transactions.

United States

The ESIGN Act (Electronic Signatures in Global and National Commerce Act, 2000) and UETA (Uniform Electronic Transactions Act) make electronic signatures legally valid for virtually all business contracts in every state.

What cannot be signed electronically?

There are narrow exceptions. Wills, property conveyances, certain court documents, and some regulated financial instruments may require wet signatures or notarisation depending on jurisdiction. For the documents most businesses send to clients - service agreements, NDAs, consent forms, onboarding paperwork, engagement letters - electronic signatures are fully enforceable.

The three types of electronic signature

If you have researched e-signatures before, you have likely seen these terms. Here is what they mean and which one your business actually needs:

NuDoc uses Simple Electronic Signatures. This is the right level for nearly every document a business sends to a client. Adding identity verification requirements before a client can sign a service agreement creates friction and delays - without adding any meaningful legal protection for standard commercial agreements.

How NuDoc creates a legally valid signed document

When a client signs through NuDoc, the system automatically captures and records the following evidence:

• Name and email address - verified by the unique link sent directly to their inbox
• Date and time - recorded in UTC at the moment of signing
• IP address - the network address used to submit the signature
• Document hash (SHA-256) - a unique fingerprint of the original file, proving it has not been altered since it was sent
• Signed document hash (SHA-256) - a fingerprint of the final signed PDF

All of this is embedded directly into the signed PDF as a certificate page. The audit trail travels with the document - it is not stored separately in a dashboard that could become inaccessible. If a dispute arises, you open the PDF and everything is there.

How to get a document signed electronically - step by step

Here is the complete flow from PDF upload to signed document in your dashboard.

Step 1 - Upload your document

Go to Signatures in your NuDoc dashboard and click New signature request. Upload the PDF you want signed. This could be a contract, consent form, engagement letter, NDA, or any other document.

Step 2 - Select the client and add context

Choose the client from your contacts list - or add them on the spot. Give the request a clear title (for example: "Consulting agreement - May 2026") and add an optional message. The message appears at the top of the client's signing page.

Step 3 - Send the request

Click Send. Your client receives an email with a secure, unique link. The link is tied to their email address and expires after 30 days.

Step 4 - Client reviews and signs

Your client clicks the link and is taken to a clean signing page that shows:

1. Your logo and brand colour (on Pro and Agency plans)
2. An embedded PDF viewer so they can read the full document before signing
3. A signature panel with three signing options

The three signing options are:

• Click to sign - the simplest option. One click confirms their identity using the email address the link was sent to. No drawing required.
• Draw - the client draws their signature using a mouse, touchpad, or finger on a touchscreen
• Type - the client types their name, which is rendered in a signature-style font

All three are equally valid under UK, EU, and US law.

Step 5 - Signed PDF delivered instantly

The moment the client signs, NuDoc:

• Appends the certificate page to the PDF
• Emails the signed copy to the client immediately
• Updates the request status in your dashboard to Signed

You can download the signed PDF at any time from the request detail page.

What the certificate page looks like

Every document signed through NuDoc gets a final page appended to it. This page contains:

• Signer name
• Signer email address
• Date and time (UTC)
• IP address
• Document title
• SHA-256 hash of the original document
• SHA-256 hash of the signed document
• "Electronically signed via NuDoc (nudoc.io)"

The hashes are what make the audit trail tamper-evident. If anyone edits the PDF after signing - even changing a single word - the hash will no longer match, immediately flagging the document as modified.

NuDoc vs DocuSign: what is the difference?

NuDoc is built for businesses that need to both collect documents and get them signed - not just the signature step in isolation. If you are already managing client document requests, adding e-signatures does not require a separate tool.

Frequently asked questions about electronic signatures

Does my client need a NuDoc account to sign? No. Your client receives a link by email, clicks it, reviews the document, and signs. No account, no password, no app required.

Are electronic signatures legally binding in the UK? Yes. The Electronic Communications Act 2000 and UK eIDAS make simple electronic signatures legally valid for commercial contracts. They are admissible as evidence in UK courts.

What is the difference between an electronic signature and a digital signature? An electronic signature is the broad legal concept - any digital method of indicating agreement. A digital signature is a specific technical implementation using public-key cryptography. Electronic signatures do not require digital signature technology to be legally valid.

What file types can I upload for signing? PDF only. Convert Word or other documents to PDF before uploading to lock the formatting and ensure the document hash is stable.

Can I resend the signing request if the client has not responded? Yes. Open the signature request in your dashboard and click Resend. Your client receives a fresh email with the same signing link.

Is there a limit on signature requests? No. Signature requests are unlimited on all NuDoc plans, including Starter.

Do I need to upgrade to use electronic signatures? No. Electronic signatures are included on every plan - Starter, Pro, and Agency - as well as the free 14-day trial.

What happens when a client declines to sign? The client can click Decline on the signing page. The request status updates to Declined in your dashboard. You can contact the client and resend when ready.

Are signed documents stored securely? Yes. Both the original and signed PDFs are encrypted at rest using AES-256. All transfers use TLS.

Can I use NuDoc e-signatures for international contracts? Simple Electronic Signatures are recognised in the UK, all EU member states, and the US - covering the vast majority of international business contracts.

Electronic signatures remove one of the last remaining reasons a business needs to ask a client to print something. Your client gets a link, reads the document, clicks sign, and receives their copy immediately. The whole process takes under two minutes from their side and zero follow-up from yours.

Start your free 14-day trial - no credit card required. Send your first signature request in minutes.