A client accepts your proposal with an electronic signature. Does that hold up? This guide explains the three eIDAS signature levels, what an audit trail must contain, when a qualified signature is needed, and how the UK and US compare.
An electronically signed proposal is a proposal that the client accepted by signing online, and under EU law that acceptance is legally valid. The rule is Regulation (EU) 910/2014, known as eIDAS, and the relevant provision is Article 25. Article 25(1) says that an electronic signature shall not be denied legal effect or admissibility as evidence in legal proceedings solely because it is in electronic form or because it does not meet the requirements for a qualified electronic signature. This is the non-discrimination principle. Article 25(2) adds that a qualified electronic signature has the equivalent legal effect of a handwritten signature. Together they mean that a typed name, a drawn signature or a click-to-accept on a proposal can all be valid, and that the question in a dispute is not "was it electronic" but "can you prove who signed what, and when". This article is general information for sales teams and not legal advice.
eIDAS defines three levels, and the differences are about evidence, not about validity. 1. Simple Electronic Signature (SES): data in electronic form attached to or logically associated with other data and used by the signatory to sign. A typed name, a drawn signature, or a click on "I accept" combined with an email verification. Valid, and its weight as evidence depends on the audit trail around it. 2. Advanced Electronic Signature (AES): uniquely linked to the signatory, capable of identifying the signatory, created with data under the sole control of the signatory, and linked to the signed data so that any later change is detectable. In practice this requires a certificate issued to the individual signer. 3. Qualified Electronic Signature (QES): an AES created with a qualified signature creation device and based on a qualified certificate from a trust service provider on the EU trusted list. Legally equivalent to a handwritten signature, and it typically involves identity verification with an ID document. Many commercial e-signature products, including Proposal Expert, deliver a SES with strong evidence. Vendors that describe a click-and-email flow as "advanced" are stretching the definition. Ask which level a product actually provides.
For a commercial proposal between two businesses, a SES with a complete audit trail is the working standard, because there is usually no form requirement for the contract in the first place. Many B2B agreements in EU member states can be concluded orally or by email, so the signature question is one of proof rather than form. Where a national law does require a specific form, for example a written form with a handwritten signature for certain real estate transactions, consumer credit agreements, or documents that need notarisation, a SES is not enough and you need a QES or a paper signature. The practical test is this: would this agreement have been valid through an email exchange? If yes, a SES with an audit trail puts you in a stronger position than that email, not a weaker one.
Under Article 25(1) the signature is admissible, and the audit trail is what makes it persuasive. A complete trail for a proposal signature contains at least the following. 1. The name of the signer as entered, and the email address the signing link was sent to. 2. Proof of control of that email address, for example a one-time code (OTP) sent by email and entered before signing. 3. The IP address and user agent of the signing device. 4. A timestamp for every event: sent, opened, code verified, signed. 5. A cryptographic hash of the document as it was at the moment of signing, so any later change can be detected. 6. A sealed PDF that bundles the signed document, the audit trail and a trusted timestamp under RFC 3161, applied by an independent time-stamping authority, so the time of sealing can be verified without trusting the vendor. Proposal Expert records all six. The signed proposal, the audit trail and the RFC 3161 timestamp are delivered as one sealed PDF that both parties can keep. If a vendor cannot show you a sample audit trail before you sign up, that is the moment to ask why.
Use a QES when the law or the counterparty requires it, not by default. Typical cases: agreements that require a written form under national law, public procurement contracts in some member states, certain financial and insurance documents, and situations where the identity of the signer is likely to be disputed and the amount justifies the cost. A QES costs money and time. The signer needs to verify their identity with a provider, often through a video call or a national eID scheme, and each signature has a per-transaction price. For a proposal worth €15,000 with a client you have met, that is disproportionate. For a €2 million framework agreement with a party you have never met, it may be exactly right. Proposal Expert does not offer qualified signatures. If you need one, sign the final contract with a QES provider and use the proposal signature for the commercial acceptance that precedes it.
After Brexit the UK kept eIDAS in domestic law as "UK eIDAS", with the same three levels and the same non-discrimination principle, alongside section 7 of the Electronic Communications Act 2000, so a SES with an audit trail is treated in the same way for commercial proposals in the UK. In the United States the federal ESIGN Act of 2000 and the Uniform Electronic Transactions Act (UETA), adopted by 49 states, give electronic signatures the same legal effect as handwritten ones for commercial transactions in general, with a requirement of intent to sign and consent to do business electronically, and no tiered system like eIDAS. Cross-border deals between an EU seller and a UK or US buyer are therefore usually fine with a SES, provided the audit trail shows intent and identity.
Plainly: a Simple Electronic Signature within eIDAS, with the full audit trail described above and a sealed PDF with an RFC 3161 timestamp. It is not an advanced or qualified signature, and the product describes it that way. Every signature request also comes with real-time tracking and an engagement score from 0 to 100, so you know the proposal was read before it was signed. The signature flow works in all 16 languages. Plans start with a free plan of 3 proposals per month and 25 AI credits, then Starter at €24 per month and Professional at €59 per month. For a B2B proposal that would otherwise have been accepted by email, that combination gives you more evidence than the email did.
Yes. A typed name is a Simple Electronic Signature and cannot be denied legal effect solely because it is electronic. Whether it is convincing in a dispute depends on the surrounding evidence, which is why the audit trail matters.
A client can dispute any signature, electronic or on paper. With a SES the party relying on the signature has to show who signed, and a trail with email verification, IP address, timestamps and a document hash is what meets that burden.
It should, if the PDF is sealed with an independent RFC 3161 timestamp and contains the audit trail. Download and archive the sealed PDF for every signed proposal, so validity does not depend on the vendor keeping its servers online.