Two questions hiding inside one

"How long is an electronic signature valid?" sounds like a single question, but it's really two, and they have different answers. The first is legal: does the signature stay enforceable as time passes? The second is practical: will you still be able to prove it years from now? The first answer is reassuring and simple. The second is where the real work lives — and where teams who assumed "signed means done forever" get caught out.

This is about the difference between a signature being valid and a record being verifiable, and what you actually have to do so both survive a decade in a drawer. Don't confuse it with reminders and expiration, which govern how long a signer has to complete a request — a totally separate clock that runs only before signing.

The signature itself doesn't expire

Start with the good news. An electronic signature carries no built-in expiration date. Under US ESIGN and UETA — and under eIDAS for European counterparties — a validly executed electronic signature has the same legal effect as a wet one, and a wet signature doesn't lapse either. A contract you e-signed five years ago is exactly as binding today as the day it completed. The agreement lasts as long as the agreement says it lasts; the signature doesn't time out underneath it.

So if someone asks "is our signed contract from 2021 still valid?" the answer is yes, the same way a paper one would be. Validity isn't the thing at risk over time. Provability is.

What's actually at risk: being able to prove it later

The real exposure is evidentiary. Years later, if a counterparty disputes the agreement, "it's valid" isn't enough — you have to show it: produce the signed document, prove this specific person signed it, and prove not a byte has changed since. That ability degrades not because the signature expired, but because the evidence around it can decay if you don't preserve it:

  • The file gets lost or replaced. A signed PDF buried in someone's old inbox, on a laptop that was wiped, isn't evidence you can produce.
  • The evidence gets separated from the document. If the audit certificate lives somewhere other than the signed PDF, in ten years you may have one without the other.
  • Nobody can verify the seal. A signed document is sealed with a SHA-256 hash and an RFC 3161 trusted timestamp. Those are designed to be checkable far into the future — but only if you kept the certificate that lets someone check them.

The signature stayed valid the whole time. What you lost was the proof, and in a dispute the proof is the only thing that counts.

What makes a signed record last

Long-term verifiability is mostly a discipline of preservation, and it's not complicated:

  • Keep the document and its certificate together. Archive the completed PDF and its audit certificate as a pair, for the document's full retention period. The certificate is what lets a third party re-verify the seal years later without trusting anyone's word.
  • Store it somewhere durable and searchable — a real system of record, not a folder of email attachments. If you can't find the signed file on demand, you effectively don't have it. This is the first habit of securing signed documents.
  • Don't rely on a single copy in one place. Retain it where it survives a wiped laptop or a departed employee.
  • Capture the metadata you'll search on — counterparty, effective date, renewal window — so you can actually retrieve the agreement when it's questioned. This is where contract lifecycle management earns its keep.

The cryptographic seal does the heavy lifting on integrity; your job is simply to make sure the sealed file and its certificate still exist and can still be found when you need them.

A note on the seal's longevity

The SHA-256 hash and trusted timestamp are built for the long haul: anyone can independently confirm, years later, that the file is byte-for-byte what was signed and that it existed in that form at the stamped time — offline, without trusting the platform. That's precisely what makes a preserved e-signed record more durable as evidence than a scanned wet-ink page, which carries no such independently checkable proof. The technology is engineered to outlast the dispute; the failure mode is almost always a human one — the file or its certificate wasn't kept.

The takeaway

An electronic signature doesn't expire — a contract you e-signed is as valid years later as the day it completed, the same as wet ink. What can decay is your ability to prove it, and that's entirely within your control: keep the signed PDF and its audit certificate together, store them somewhere durable and searchable for the full retention period, and capture the metadata you'll need to find them. Do that and a signature stays not just valid but provable for as long as the obligation runs. The seal is built to last; make sure the record does too.

This article is general guidance, not legal advice. For retention periods and recordkeeping requirements specific to your documents or jurisdiction, consult qualified counsel.