Do you always need to sign a bid electronically?
An electronic signature on a bid is not required in every case: it depends on what the tender rules for the contract in question demand. Submitting a bid on a buyer's e-procurement portal and signing it are two separate steps: you can submit without an electronic signature being required at that stage, with the buyer able to request it from the winning bidder at the award stage instead. Some buyers require the signature as early as submission, others only from the successful bidder. The rule for a given contract appears in its tender rules, which are the source to read before anything else.
A common mistake is assuming there is a single rule. There isn't one: each contract sets its own signature requirements, and assuming a signature is or is not required without checking risks a poorly executed bid or a rejection.
What is an electronic signature, and how does it differ from a scan?
An electronic signature is a technical process that ties a signer's identity to a document and guarantees its integrity, using a certificate issued by a trust service provider. It should not be confused with a scanned image of a handwritten signature, which does not carry the same legal value: a scan pasted into a document proves neither the signer's identity nor that the document has not been altered since signing. In the European Union, electronic signatures fall under a common framework that distinguishes several levels, from simple to qualified; other markets have their own electronic-signature frameworks.
This distinction matters: when a buyer requires an electronic signature at a given level, a scan or a lower-level signature does not meet the requirement, and the bid may be treated as not validly signed.
What level of electronic signature should you use?
The level of electronic signature to use is whatever the tender rules require, often an advanced signature backed by a qualified certificate. The buyer states the required level and, sometimes, the accepted signature formats. The company needs, in the name of the authorized signer, a matching certificate obtained from a trust service provider, and should allow time to get one: a certificate cannot be obtained in the hour before submission.
Checking the required level early, and holding the right certificate, is part of preparation just as much as drafting is. An excellent bid that is improperly signed can be rejected on purely formal grounds.
Electronic signature: when, on what, at what level?
Signature requirements come down to three questions. The table below links each question to what to check in the tender rules.
| Question | What to check | Where to find it |
|---|---|---|
| When to sign | at submission or at award | the tender rules |
| What to sign | which documents must be signed | the tender rules |
| At what level | the signature level and format required | the tender rules |
This table brings every uncertainty back to a single source: the tender rules. Signature requirements are not a matter of custom; they follow the contract's written requirements.
When is a quick check enough, and when should you prepare in advance?
For a contract where the signature is only requested at award, a quick check of the tender rules is enough to remove any doubt at submission. For a contract requiring an electronic signature as early as submission, preparing in advance becomes essential: obtain the certificate at the right level, in the right signer's name, and test it before submission day. The line is timing: the earlier the signature is required, the earlier it needs to be prepared.
Securing the signature of a bid, in order
- Read the tender rules: when, what, and at what level to sign.
- Identify the authorized signer for the company.
- Obtain the certificate at the required level, from a trust service provider.
- Test the signature on a document, before submission day.
- Sign the required documents in the format the buyer accepts.
- Check at submission that the signed documents are the ones actually uploaded.
On the Optivalue.ai platform, which publishes this site, 85 specialized agents (72 subject-matter agents, 12 sector-specific agents, 1 librarian agent) flag, among the file's requirements, those bearing on the format of submission, including the signature, so none is discovered the night before submission.
Frequently asked questions
Is a bid always rejected if it is not electronically signed?
A bid without an electronic signature is only rejected if the tender rules required the signature at that stage. When the signature is only requested at award, its absence at submission is not a ground for rejection.
Is a scanned handwritten signature enough?
A scanned handwritten signature does not count as an electronic signature: it guarantees neither the signer's identity nor the document's integrity. When an electronic signature is required, a scan does not meet the requirement.
Who should sign the bid within the company?
The person authorized to commit the company, or their duly appointed delegate. The signature certificate must be issued in that person's name, which means planning ahead.
How long does it take to obtain a signature certificate?
The time needed depends on the trust service provider and the level requested. It is not instant: arrange it well before the submission period.
Check the formal requirements of a real file
Bring a real set of tender documents. You will see requirement-extraction coverage, including format and signature requirements, sources cited on every page, and a gap analysis of your response, not a prepared demo.
Written by the compliance and presales team at Optivalue.ai. Last reviewed: 5 September 2026. This page does not constitute legal advice.
Sources cited
- Electronic-signature frameworks: within the EU, the regulation on electronic identification and trust services (signature levels from simple to qualified); other markets have their own frameworks, to be mapped to the requirements of the market in question.