- SES proves only that someone clicked a button — no identity, no integrity, no audit trail.
- After signing, an SES document can be modified and the signature still appears valid.
- AES is the minimum standard for any contract that matters — verified identity, tamper evidence, audit log.
- QES is the maximum tier: equivalent to a handwritten signature, recognised across borders.
This is the problem with simple electronic signatures. They're simple. That's also why they're useless for anything that matters. The five minutes you save with SES can cost you five months in litigation when the signature doesn't prove what you thought it proved.
Simple electronic signatures: fast but foolish
A Simple Electronic Signature (SES) is basically a digital name scrawled on a document. It proves you signed something. That's it. It doesn't prove who you are. It doesn't prove the document hasn't been altered. It doesn't prove you understood what you were signing. It's the legal equivalent of a pinky promise.
Here's what an SES actually does: it proves signing occurred. Someone clicked a button on this specific document. That's all.
- It doesn't verify identity. Could be you. Could be someone using your email. The system doesn't care.
- It doesn't prove the document is unaltered. A contract can be modified after signing and the signature still appears on the final version.
- It doesn't hold up for sensitive documents. Courts have ruled SES insufficient for contracts, financial documents, healthcare records and property transactions.
- It provides no audit trail. When did you sign it? From where? On what device? SES doesn't care.
Using an SES for a legal document is like locking your front door but leaving all your windows open. You've done something that looks like security. You haven't actually secured anything.
Why your contracts are vulnerable with SES
Walk through a real scenario that happens more often than anyone wants to admit. You're a consultant. You sign a statement of work with a client using an SES-only platform. You receive partial payment. Three months in, the client disputes the terms. They claim the version they signed has different payment terms than the version you signed. They change the document in their files and claim you agreed to this version.
Your SES doesn't help you. It proves you signed something. It doesn't prove what version you signed or that it hasn't been modified. The contract is vulnerable. You have a signature on a document but no evidence of what the document actually said when you signed it.
If you'd used an Advanced Electronic Signature (AES), the document would be cryptographically sealed. Any modification after signing breaks the seal and is immediately visible. You'd have timestamped proof of exactly what version you signed and when. The dispute becomes trivial to resolve.
This isn't a rare edge case. It's a real legal vulnerability that exists every time you use SES for something that matters.
The bigger problem: identity uncertainty
With an SES, the signature proves nothing about who actually signed the document. You're finalizing a contract with a new vendor. The SES appears to be from their CFO, john@vendor.com. Except it's not their CFO. It's their IT person using the CFO's email (which happens), or someone spoofing the address, or someone who has access to the account.
Did the company actually authorise this? You don't know. The SES doesn't verify anything. It just means someone with access to that email signed a document. For a legal contract, that's nowhere near sufficient.
This is why courts have increasingly rejected SES for contracts. It doesn't prove authorisation. It proves a signature appeared.
“An SES doesn't prove authorisation. It proves a signature appeared. Those are not the same sentence.”
AES: what you should actually use
An Advanced Electronic Signature requires reasonable authentication. You verify the signer's identity. The document is cryptographically sealed after signing. Any modification is immediately visible. You get a timestamped audit trail of who signed what when.
This is legally sufficient in virtually every jurisdiction for most contracts, financial documents and business agreements.
- 1Identity verification
The provider confirms you are who you claim to be. Not foolproof, but reasonable.
- 2Document integrity
The document is sealed. Any modification after signing is detectable — and visible.
- 3Audit trail
A timestamped record of everything: who signed, when, from where, on which device.
- 4Legal weight
Courts recognise AES as sufficient evidence of authorisation and consent for most business documents.
For employment contracts, vendor agreements, NDAs, SOWs, change orders, financial commitments: AES is the minimum standard. Not because it's "best practice." Because anything less is legally irresponsible.
QES: when you need maximum assurance
A Qualified Electronic Signature requires verified identity from a qualified trust service provider. Think of it as notarised electronic signing — the highest level of assurance.
Use QES when:
- You're signing something that might end up in court with international parties.
- You're dealing with sensitive intellectual property.
- You're committing serious financial resources.
- You're cross-border and want zero ambiguity about who signed what.
QES takes longer and costs more. But for high-stakes documents, it's insurance worth buying.
The real risk of using the wrong level
Let's be concrete.
Scenario 1: SES for an employment contract. Employee works three months, then claims they never agreed to the terms. They produce evidence that someone with access to HR email could have signed it. Goes to court. Your SES doesn't prove anything. You might lose the case or settle expensively.
Scenario 2: SES for a vendor contract. Vendor claims they signed a different version than the one you're enforcing. The SES doesn't prove the document hasn't been modified. You're in a dispute that SES can't resolve.
Scenario 3: SES for a financial commitment. Someone signs something they claim they didn't authorise. The SES proves someone with their email signed it. It doesn't prove they actually clicked the button. You're defending against a claim that SES can't definitively refute.
These aren't hypothetical. They're litigation scenarios that happen when companies get signature levels wrong.
Why swipesign doesn't even offer SES
Some e-signature providers offer SES because it's cheap and easy. They make money from volume. swipesign deliberately doesn't offer SES for legal documents — because the platform respects its users more than it respects transaction volume.
Check out swipesign's signing options to see what signature levels are actually available. If a provider is offering SES for contracts, ask yourself why they're willing to sell you something that won't actually hold up.
The real cost of using wrong signature levels isn't the signature itself. It's the dispute that follows when the signature doesn't prove what you thought it proved.
If your legal documents are signed with SES, you don't have a contract. You have a digital doodle that someone claims they made. The difference matters more than you think.