Peer-to-peer commerce

Keep existing listing, item photos, messages and exchange records without certifying the meeting, payment or the other person's identity.

Keep existing listing, item photos, messages and exchange records without certifying the meeting, payment or the other person's identity. Keep your original source records together, then date the exact files. It does not prove identity, origin, truth, location, sending, delivery, consent, authorization, completeness, rights, acceptance or outcome.

Try a file locally

Your photos and files stay on your device, so keep them.

EXAMPLE

In-person private sale meetup where buyer and seller confirm item, condition and exchange, often at a designated safe exchange spot

1 Nov 2026

Authority time: 14:02 UTC · example
Bitcoin block time: 14:10 UTC · example
Last checked: 15:02 UTC · example

✓ Dated◆ Permanent

Now keep it safe: three things

Keep your photos and files unedited. The receipt only matches the originals. Put them in an album such as “My records”.
Save this receipt to your camera roll.
Keep the receipt file too. The image is a handy copy; checking needs the file.
Email it to yourself.Email it to myself
Your mail app opens a draft. Attach your receipt image and receipt file. Don’t attach your photos or documents. Timevolt does not send it or know whether it was sent.

Your record, one step at a time.

Your photos and files stay on your device, so keep them.

Local preview: files are fingerprinted here. Notes and progress stay in this browser. Keep downloaded copies; browser storage is not a backup.

1. Original files for this record0 items

How?

Add the exact original files for this part of the record. Keep them unchanged; a different export or edit has a different fingerprint.

Add files

Add link and screenshots

Link to recordAdd screenshots

The link is recorded, not fetched or verified.

2. Write down anything you need to remember0 items

How?

Record the date, time, place and who you spoke to. New notes are saved separately rather than editing an old note.

How to keep notes that hold up

Write it down

New note

By making a receipt you agree to the Terms and Privacy Policy. The Bitcoin record is permanent.

Photo of note

By making a receipt you agree to the Terms and Privacy Policy. The Bitcoin record is permanent.

How to keep notes that hold up

Write notes as soon as you can. Keep the original account rather than replacing it later; the venue decides what weight it gets.

Write it down straight away, on paper or in the box on a step.
Put the date, time and place at the top, and who you spoke to.
Use their words where you can; separate what you saw from what you were told.
Sign or initial a paper note, photograph it and add the photo.
Never edit an old note. Add a new dated entry when something changes. A device save time is not independent time evidence or proof of event order.

In-person private sale meetup where buyer and seller confirm item, condition and exchange, often at a designated safe exchange spot

01 · Keep the exact files

Keep the original files for in-person private sale meetup where buyer and seller confirm item, condition and exchange, often at a designated safe exchange spot. Include any existing photos, signed records and source-system exports.

Records to keep: Existing capture-system and sign-off records

In-person private sale meetup where buyer and seller confirm item, condition and exchange, often at a designated safe exchange spot

02 · Date the file’s code

Your device fingerprints the selected file or manifest. Dated follows an independent timestamp; Permanent follows Bitcoin anchoring.

An independent time, tied to the exact bytes.

In-person private sale meetup where buyer and seller confirm item, condition and exchange, often at a designated safe exchange spot

03 · Keep the evidence

Keep the original files and complete receipt separately, alongside any existing venue, signature and workflow records.

Keep the originals too. A changed or compressed copy has a different fingerprint.

Try a file. It stays here.

Make a test receipt on this device.

By making a receipt you agree to the Terms and Privacy Policy. The Bitcoin record is permanent.

Choose a file

or drop a file here

Real cases: why the saved copy matters.

Real cases where dated records mattered. We don’t claim a time receipt would have changed the result.

British Columbia, Canada · 2025

Record which item the sale promises

A buyer tested a phone at a meetup, then found it was not genuine. Texts and a witness showed the deal was for a genuine phone. A report says the tribunal ordered a refund despite the seller’s no-refunds term.

Indexed news report checked; the direct article was unavailable. Tribunal decision not checked. This was a contract ruling, not a criminal finding.

Summarized on Oct 29, 2026

Read the source ›

Related cases

What courts, schemes and regulators say.

Positions below refer to the cited rule or record type, not endorsement of Timevolt. This service is not represented as an eIDAS qualified timestamp provider. A non-qualified timestamp does not receive the qualified timestamp presumption.

Needs something else · OfferUp current operator guidance

Meetup safety guidance updated 31 August 2026

Guidance distinguishes platform messages, item inspection and meeting arrangements from the actual exchange.

Provider guidance, not guaranteed safety or acceptance of Timevolt. No financial or personal-security plan provided.

Source summary as of 2026-10-29. Check the current source and applicable local rules.

Read the source

Unclear · Canada British Columbia New Westminster

Police exchange-location and evidence request

Police invite lobby exchanges and request witnesses/CCTV in the reported investigation.

Official investigation account 8 July 2025, not a conviction or certification of exchanges. Monitored location is not staff witnessing or a custody guarantee.

Source summary as of 2026-10-29. Check the current source and applicable local rules.

Read the source

Unclear · New Zealand private vehicle purchases

Consumer Protection evidence guidance

Original listings, messages, payment records, photos and inspection reports are listed as potentially useful records.

Vehicle-specific usefulness guidance, not an admissibility promise or general rule for all goods; no substantive legal remedy advice adopted.

Source summary as of 2026-10-29. Check the current source and applicable local rules.

Read the source

Other ways to do this

Prices change. Check each provider’s site for current prices and service details.

OfferUp Community MeetUp Spots workflow
Provides designated public meeting locations and in-app arrangements.
Visit site
AA existing private-sale record form
Provides Vehicle-specific existing sale details and acknowledgments.
Visit site
New Westminster Police lobby location
Provides police say their monitored lobby is available for exchanges.
Visit site

Related workflows.

Proves / Doesn’t prove

Proves

A completed time receipt shows that the exact selected file existed by the independently witnessed time. You can check whether a later copy has the same bytes. It does not establish creation time, authorship, identity, event order, location or the truth of the contents.

Doesn’t prove

It does not prove identity, origin, truth, location, sending, delivery, consent, authorization, completeness, rights, acceptance or outcome.

These are the bounds of a completed proof. The local tester does not establish any time. The chosen court, scheme or regulator decides what to accept.

Questions, answered plainly.

Your file stays on your device. During normal receipt creation, your device sends a randomized code made from its fingerprint, plus encrypted recovery data. It doesn't send the plain fingerprint or the random value that opens the code. Keep the original file and the complete receipt for checking. Privacy Policy.

Does a venue code prove both people attended?

No. OfferUp describes designated places, not independent certification of every exchange; a file date cannot establish attendance.