Most e-signature vendor evaluations focus on price, integrations, and UX, and skip the question that matters most once a document is disputed: can the signature prove itself independently of the vendor. Six questions to ask before you sign, not after.
Feature comparisons for e-signature tools tend to focus on workflow, integrations, and per-seat pricing, real considerations, but ones that say nothing about what happens when a signed document is challenged. That question only comes up after you’ve already committed to a vendor and a signing process, which is exactly the wrong time to discover the answer.
Ask specifically: if you exported a signed document and never logged into their platform again, could a third party still confirm it’s genuine? An embedded PAdES, XAdES, or CAdES signature travels with the file. A signature that’s only recorded in the vendor’s database means the proof depends on that vendor answering, indefinitely. See the risk of platform-tied signatures.
A signature is only as trustworthy as the certificate behind it. Ask whether their certificates chain to the EU List of Trusted Lists (LOTL), which carries EU-wide legal recognition for qualified signatures and seals, or only to a private or self-issued root, which carries none. A vendor that can’t answer this clearly is itself an answer.
These carry meaningfully different legal weight under eIDAS Article 25, and vendors don’t always default to the level you assume. Ask them to state it plainly per plan tier, not just market the feature as "legally binding e-signatures" in general. See is my e-signature legally binding?
Ask whether they support long-term validation profiles (PAdES-B-LTA) that embed the evidence needed to check a signature years after the signing certificate itself has expired. For anything with a multi-year lifecycle, a lease or financing agreement, this determines whether the document is still provable a decade out. See future-proofing signed contracts.
A qualified signature is for a named natural person and carries handwritten-signature equivalence. A qualified seal is for a legal person (a company) and carries a different legal effect, integrity and origin, not handwritten equivalence. If your use case is a company issuing documents at scale, ask whether the vendor is actually offering seals, not signatures issued under a shared company identity. See what is a qualified electronic seal?
Ask this before you sign the contract, not after you’re trying to leave. If the vendor’s signatures are embedded and independently verifiable, your existing documents stay provable regardless of what you do next. If they’re not, migrating away can mean losing the ability to prove your own historical agreements are genuine.
A vendor confident in its compliance posture will answer these questions specifically: which format, which trust list, which legal level, without redirecting to marketing language like "bank-grade" or "legally binding" used as a catch-all. Vague answers to specific technical questions are themselves informative.