This scenario sounds familiar
You sent a quote by email, the client accepted verbally or by message, work began. Then payment time comes, and suddenly the client claims they never received the quote, disputes the amount, or says the terms were different. Without independent timestamped proof, it's your word against theirs. Even with an email, a bad-faith client can claim it was forged or backdated.
Responding to the dispute: your concrete options
- Gather all existing evidence: emails, messages, timestamped screenshots.
- Send a formal demand by registered email with acknowledgment of receipt.
- Contact a freelance association or specialized lawyer.
- If the amount is under €5,000, file with the small claims court without a lawyer.
ProofStamper cannot resolve an ongoing dispute — it protects for the future. For an active dispute, consult a legal professional.
Next time, have proof before sending
You finalize a quote or contract before sending it to the client.
You generate a timestamped proof of the document in 30 seconds.
You can prove this exact document existed at this exact date, before any sending.
The file never leaves your device. Only the SHA-256 fingerprint is transmitted.
An email can be disputed — RFC 3161 proof cannot
Three approaches, only one is unfalsifiable.
| Criterion | Regular email | Registered email | ProofStamper |
|---|---|---|---|
| Cost | Free | ~€5 / send | Free |
| Delay | Instant | 24–48 h | 30 seconds |
| Falsifiable | Yes | Difficult | No (RFC 3161) |
| Third-party verifiable | No | No | Yes ✓ |
| Accepted formats | Attachment | Paper / PDF | All |
| Usable before sending | No | No | Yes ✓ |
| Free | Yes | No | Yes |
3 steps before each quote sending
- Upload your finalized quote: PDF, Word or any other format.
- Automatic local certification: SHA-256 hash computed in browser + RFC 3161 timestamp via FreeTSA.
- Download your Proof Pack: PDF certificate + .tsr token. Send the quote with proof attached.
Frequently asked questions
- Would this proof have been enough to resolve my current dispute?
- If you had timestamped the quote before sending, you would have RFC 3161 proof showing this exact document existed at that date. This is strong evidence for a mediator or court.
- Can my client challenge the validity of this proof?
- The RFC 3161 certificate is issued by a third-party timestamp authority (FreeTSA). It can be independently verified by anyone, without an account or special software.
- Should I send the certificate together with the quote?
- Recommended. Attach the Proof Pack (ZIP) to your quote email. The client will immediately know the document is timestamped and can verify its authenticity.
- Does this proof have legal value in court?
- The RFC 3161 certificate constitutes technical proof of prior existence. It can be presented as evidence in court. To strengthen its value, you can complement it with a bailiff's report.