Terms of sale

These terms cover the one thing Existamp sells: the certified timestamp, at £2.99 a set. Everything else is free and needs no account: the fingerprints, the Bitcoin timestamp, the receipt and the checker. You never need to pay to make, keep or check a receipt.

Who we are

Existamp is run by Avant Partners Limited, a company registered in England and Wales, company number 17447921. Registered office: 24 Westbourne House, Richmond Road, Twickenham, TW1 3AS, United Kingdom. Email: io@existamp.com.

What you buy

One certified timestamp for one set of files. When you pay, you get a code, and the app uses it straight away on the finished set you paid from. (You can also enter a code on a finished set's page, under “I already have a code”.) Our server sends the set's fingerprint, and nothing else, to a qualified trust service provider, which adds its own timestamp within seconds. Your phone checks the answer and keeps it with the set; save the set to your files to put it in your zip. UK law presumes a qualified timestamp's date and time are accurate unless shown otherwise.

A code works once, for one set, for 12 months from the day you buy it. The free Bitcoin timestamp is added to the set either way. What the certified timestamp rests on, and who the providers are, is on How it works.

Paying

Payment is taken by Link, part of Stripe, which sells the timestamp for us as the seller of record (you'll see “Sold through Link”). Link takes the payment, works out any tax, and sends your receipt. Your statement will show LINK.COM* EXISTAMP. Link's own terms apply to the payment: link.com/terms.

Link shares the details you give at checkout, such as your name and email, with us in Stripe's dashboard. Our server never receives them, and nothing links a payment to a set. See Privacy.

If the timestamp doesn't arrive

If no provider answers, your code isn't used up: try again later. We keep no copy of your timestamp, so if your code is used up but your phone didn't get the certified timestamp, write to us at io@existamp.com and we'll give you a new code or your money back.

Cancelling and refunds

You can cancel within 14 days of buying and get your money back, whether or not you have used the code. Ask Link's support at support.link.com and give “cooling off period” as the reason, or write to us at io@existamp.com.

After 14 days, we refund a code that doesn't work, or a payment that brought no timestamp. A refund can't undo a timestamp already made: the provider's signature stays valid in your zip.

What we can't promise

We can't promise that the providers will always answer, or that whoever settles a dispute, such as a deposit scheme, a court or a hire company, will give the timestamp any particular weight: they decide what evidence they rely on. The law the certified timestamp rests on can change; How it works says how. Existamp is not legal advice.

If we get something wrong, tell us and we'll put it right or refund you. Nothing in these terms takes away your rights as a consumer.

The law that applies

These terms are under the law of England and Wales. If you live in Scotland or Northern Ireland, you can also bring a claim in your own courts.

Changes

Last updated 28 October 2026. If we change these terms, the new ones apply only to purchases made after the change.