Two documents come back signed. One has a signature drawn with a finger on a phone. The other reports "Signed and all signatures are valid" in a blue bar at the top of the reader. Both are legally capable of binding a contract in most commercial situations — but only one of them can prove the document has not been altered since signing.
The electronic signature vs digital signature distinction is not legal jargon. It describes two genuinely different mechanisms, and choosing the wrong one means either paying for assurance you did not need, or discovering during a dispute that you cannot prove what you thought you could.
The Short Answer
An electronic signature is any electronic indication of intent to sign — a typed name, a drawn squiggle, a tick box, a click on "I agree". It is a broad legal category.
A digital signature is a specific technology: a cryptographic operation using a certificate that binds the signature to the document and detects any subsequent change. It is one way of producing an electronic signature, not a separate legal concept.
So every digital signature is an electronic signature. Most electronic signatures are not digital signatures.
What a Drawn or Typed Signature Actually Provides
A signature image placed on a PDF is a picture. It proves nothing on its own — it can be copied from one document and pasted onto another in seconds, and the document can be edited afterwards with no trace.
That does not make it worthless. In practice, what gives a simple electronic signature evidential weight is the surrounding context: an audit trail showing who accessed the document and when, the email address or account used, IP address and timestamp, and a record of the signer's consent. Reputable e-signature platforms exist largely to capture that context, which the signature image itself does not carry.
If you are collecting a drawn signature on a PDF form with no platform behind it, be clear-eyed: you have a record of intent, not proof of integrity.
What a Digital Signature Adds
A digital signature performs a cryptographic hash of the document and encrypts it with a private key tied to a certificate. The reader recalculates the hash on opening. If anything has changed — a single character, a compressed image, a re-saved file — the hashes no longer match and the signature reports as invalid.
That gives you three things a signature image cannot:
- Integrity. Any modification after signing is detectable.
- Authentication. The certificate ties the signature to an identity, to whatever standard the issuing authority verified.
- Non-repudiation, in proportion to how rigorously that identity was checked.
A practical consequence worth planning around: because any change invalidates it, signing must be the final step. Compressing, editing, flattening or re-saving a signed PDF breaks the signature.
How the Law Frames It
Jurisdictions take two broadly different approaches, and both recognise electronic signatures as valid.
European Union
The eIDAS Regulation (EU) No 910/2014, in force since July 2016, defines three tiers:
- Simple electronic signature (SES) — data in electronic form used by the signatory to sign. A typed name or a click qualifies. Article 25(1) establishes that a signature cannot be denied legal effect or admissibility solely because it is electronic.
- Advanced electronic signature (AES) — uniquely linked to and capable of identifying the signatory, created under their sole control, and linked to the data such that later changes are detectable. In practice this means a digital signature using certificates.
- Qualified electronic signature (QES) — an advanced signature created with a qualified signature creation device and based on a qualified certificate from a qualified trust service provider. eIDAS gives a QES the equivalent legal effect of a handwritten signature across all member states.
All three tiers are legally valid. The higher tiers carry greater evidential weight, not exclusive validity — and for the large majority of commercial, HR and consumer transactions no specific tier is mandated.
United Kingdom
Following Brexit, the UK retained an equivalent framework through the Electronic Identification and Trust Services for Electronic Transactions Regulations 2016 as amended, often called UK eIDAS, keeping the same three-tier structure.
United States
A different model. The federal ESIGN Act (2000) and the Uniform Electronic Transactions Act, adopted by most states, are technology-neutral and do not define tiers. An electronic signature is defined broadly as an electronic sound, symbol or process attached to or logically associated with a record and executed with intent to sign.
Validity generally rests on four conditions: intent to sign, consent to transact electronically, association of the signature with the record, and retention of a reproducible record.
Certain document types are commonly excluded — wills, codicils and testamentary trusts among them — and specific sectors carry their own requirements.
Which One Does Your Situation Need?
| Document | Usually sufficient | Why |
|---|---|---|
| Internal approvals and sign-offs | Simple electronic signature | Low dispute risk, identity already known |
| Consent and policy acknowledgement | Simple, with audit trail | Record of intent is the point |
| Standard commercial contracts | Simple or advanced | Rarely a mandated tier |
| High-value or long-term agreements | Advanced (digital signature) | Integrity matters years later |
| Regulated or public-sector filings | Check the specific requirement | Often prescribed explicitly |
| Documents that must prove non-alteration | Digital signature | Only mechanism that detects change |
Setting Up Signing on a PDF Form
If signatures are collected on a fillable PDF, a few decisions determine whether the result is usable.
- Choose the field type deliberately. A digital signature field triggers certificate-based signing. A drawn-signature field captures an image. They look similar in a form builder and behave completely differently.
- Place date fields separately rather than relying on the signer to type one consistently.
- Consider certifying the document before distribution, which lets you permit form filling and signing while detecting other changes.
- Decide what gets archived — the signed PDF itself, the extracted data, or both. Flattening a signed document destroys the signature, so archive the signed file as it is.
- Test in the readers your signers actually use. Signature handling differs considerably between Adobe Acrobat and Reader, browser-built-in viewers, and mobile apps. A field that works in Acrobat may be unusable in a browser preview.
The wider mechanics of building these forms are covered in professional fillable PDF forms, and if part of your process would be better handled online, Jotform payment and signature workflows covers that route.
What Makes a Simple Signature Hold Up
If you are relying on a simple electronic signature, the evidential weight comes from what surrounds it rather than the mark itself. Worth capturing:
- Identity of the signer — the email address or account used, and how it was verified.
- Timestamp of when the document was opened, viewed and signed.
- Consent to sign electronically, recorded explicitly rather than assumed.
- The document version signed, so there is no ambiguity about which draft was agreed.
- Delivery evidence showing the document reached the signer.
- A retained copy both parties can reproduce.
A signature image on a PDF returned by email carries almost none of this by default. That is not a reason to avoid it for low-risk documents — it is a reason not to use it for the ones that matter.
Signatures Have to Survive the Archive
A point that only becomes apparent years later: a digital signature is validated against a certificate, and certificates expire and are sometimes revoked. Validating a signature long after signing needs evidence that the certificate was valid at the time of signing.
That is what long-term validation provisions exist for — embedding a trusted timestamp and the revocation information needed to check the certificate later, so the signature still verifies after the certificate itself has lapsed.
Practical implications for anything with a long retention period, such as contracts, deeds and regulatory records: use a timestamp from a trusted source rather than the signer's computer clock, keep the signed file exactly as signed rather than re-saving it, and store it somewhere that will not silently re-encode it. Some document management systems re-process uploads and break signatures in the process — worth testing before you trust one with signed originals.
Common Mistakes
- Assuming a signature image proves anything about the document. It does not.
- Editing or compressing after signing, which invalidates a digital signature.
- Collecting signatures with no audit trail, leaving only a picture.
- Buying qualified signatures for routine internal approvals, which is cost with no corresponding risk.
- Assuming a tier is required when no rule specifies one.
- Not checking exclusions for the specific document type.
- Using a drawn-signature field where the compliance requirement was certificate-based.
- Never testing across readers, then discovering signers cannot complete the field.
- Emailing signed documents with no retention policy, so the authoritative copy is whichever inbox it landed in.
Conclusion
Start from what you need to prove. If you need a record that someone agreed, a simple electronic signature with a decent audit trail is usually proportionate. If you need to demonstrate that the document has not changed since signing, only a digital signature does that, and it has to be the last thing applied.
Most organisations get this wrong in one of two directions: relying on a pasted image for agreements that matter, or buying qualified signatures for holiday request forms. Matching the mechanism to the actual risk is the whole decision.
Getting Signature Workflows Set Up
SBTEXMEDIA builds fillable PDF forms and document workflows for businesses, HR teams, legal firms, healthcare providers, schools and government organisations — signature and date fields configured correctly for the type of signing you need, certifying signatures where documents must permit filling but detect other changes, form field structure, validation, and testing across the PDF readers your recipients actually use.
Related work on PDF security and redaction and converting existing forms into fillable PDFs is handled by the same team.
You can see examples on the portfolio, browse the full range of services, or describe what your document needs to prove for a fixed quote and a delivery date before work begins. More guides are on the SBTEXMEDIA blog.
