Answer: contracts and signed documents
How to prove a contract wasn’t edited after signingKeep the exact signed file and record its fingerprint straight away
TimeBinder adds a layer of protection against AI and human fraud and disputes.
The file stays on your device. Your browser makes a digital fingerprint of the file. TimeBinder records the fingerprint and the time, not the file.
Short answer
You can show a signed contract has not been edited by keeping the exact signed file and recording its SHA-256 fingerprint with a time as soon as it is signed, before anyone has reason to dispute it. Later, a copy that still matches the fingerprint is the same file, byte for byte; a copy that does not match is a different file.
A timestamp shows the file existed no later than the recorded time and still matches. It does not show who signed, or that the contract is valid or enforceable.
Steps: record the signed contract
- Save the final signed file. Use the completed PDF as it came out of your signing process. If you used an e-signature service, also download its certificate of completion. Do not open and re-save the signed file.
- Make a TimeBind straight after signing. Your browser makes the fingerprint and the file stays on your device. One TimeBind holds up to 10 files, so you can include the certificate and any schedules.
- Keep the file and the Proof of Time Certificate together. Share copies, not the original.
- If the contract is challenged, compare. Check the copy in dispute against yours with the free file comparison checker, and check your original against the TimeBind. A match shows it is the same file.
- Record earlier drafts too. See how to timestamp a contract version before anyone signs.
Make the TimeBind as close to signing as you can. A TimeBind made after a dispute starts only shows the file existed from that time, not before.
Ways people try to show a contract was not changed
| Method | What it shows | Where it falls short |
|---|---|---|
| File dates and metadata | A date your device or software recorded. | Can be changed in seconds, and change on their own when files are copied or synced. |
| Email thread or email to yourself | A message and attachment sat in a mailbox. | Depends on mailbox records that you or the other side may control, lose or dispute. |
| E-signature certificate | Signing events recorded by the signing service. | Relies on that service’s records. See certificate of completion vs a timestamp. |
| Notarisation | That a notary witnessed the signing or certified a copy. | A different question (who signed). It is not a fingerprint you can later compare against a copy. See hash timestamp vs notarisation. |
| TimeBind | That the exact file existed no later than a recorded time and still matches its fingerprint. | Does not show who signed, or that the terms are enforceable. |
What a TimeBind shows, and what it does not
- It shows that this exact file existed no later than the recorded time, and that a copy shown later still matches its fingerprint.
- It does not show who made the file, who owns it, that its contents are true, or whether AI was used to make or edit it.
- It does not replace legal advice, a notary where one is required, or a court’s own view of the evidence.
First Pooled TimeBind free, no card, then from US$5. An ASAP TimeBind is US$15.
Frequently asked questions
Can a PDF be edited after it is signed?
Yes. Some PDFs carry a digital signature that can show later changes, but many “signed” PDFs are scans or flattened files with no such protection, and anyone with the right software can edit and re-save a copy. That is why a fingerprint recorded at signing is useful: a changed copy gives a different fingerprint.
Does a TimeBind prove the contract is valid or enforceable?
No. It shows only that an exact file existed no later than a recorded time and that a copy still matches it. Whether a contract is valid or enforceable depends on its terms and the law that applies. A lawyer can advise on your own situation.
What if I only have a scan of the signed contract?
Make a TimeBind of the scan file. It shows that exact scan existed no later than the recorded time. A different scan, even of the same paper, gives a different fingerprint, so keep the scan you rely on unchanged.
What if the other side has a different version?
Compare the two files. If the fingerprints differ, they are different files. If you made a TimeBind of yours at signing, it shows your version existed no later than that time. It does not show which version the parties agreed. That turns on the evidence and the law.
Can I make a TimeBind after a dispute has started?
Yes, and it still shows the file existed no later than that time and has not changed since. It cannot show the file existed before that time. For that reason, make it at signing where you can.
How much does it cost?
Your first Pooled TimeBind is free with no card, then from US$5. A Pooled TimeBind is usually recorded within 24 to 48 hours, often sooner. An ASAP TimeBind is US$15 and is broadcast straight away.
Related guides and tools
- Free file comparison checkerDrop two files and see if they are identical
- How to timestamp a contract versionRecord each draft before anyone signs
- Contract execution checklist for law firmsA client service checklist
- Timestamp vs electronic signatureWhat each one shows
- Legal timestampingFor lawyers and law firms
- All answersShort answers to common file-proof questions
Date your next signed contract free
Add a layer of protection against AI and human fraud and disputes: a dated, checkable record of the exact file you hold.
- Open the app and sign in with email or Google.
- Add your files. They stay on your computer.
- Seal them and download your Proof of Time certificates.
First Pooled TimeBind free, no card, then from US$5. See pricing.