Built for used car sellers & buyers

A bill of sale that can't be faked.

Private car sales are high-stakes. Authryn adds phone-verified signatures from both buyer and seller — so the deal is locked in evidence the DMV, your bank, or a small-claims court can trust.

Create your first receipt — freeVerify a receipt
No credit cardSet up in 30 secondsNo app to download

The trust problem on used car

You've probably been here before — or worried about it happening.

Title transfer disputes

Buyer never registers it. Tickets, accidents, and parking violations keep coming to you for months.

Bounced checks & fake cash

Cashier's checks get faked. Counterfeit bills slip past quick counts. You hand over keys and learn too late.

'As-is' arguments

Three days later: 'You said the transmission was new!' But you never said that. There's no record.

How it works

3 steps. 30 seconds. Tamper-proof.

1

Create the receipt

Type what you're selling on used car and the price. We generate a unique link.

2

Share & both verify by phone

Send the link via Messenger, SMS, or QR code. Both parties verify their real phone number.

3

Done. You're both covered.

The receipt is now cryptographically signed evidence. Nobody can claim the deal didn't happen.

Perfect for any used car deal

Private car sale
Motorcycle sale
RV / camper sale
Boat sale
Trailer transfer
ATV / dirt bike
Parts deal ($500+)
Lease takeover
“Sold my 2018 Civic for $11k. Authryn receipt had the mileage, the as-is clause, my disclosures, and both our phone-verified signatures. The buyer tried to come back two weeks later about the timing belt. One look at the receipt, and that was over.”
Anonymous seller
Private auto sale

Frequently asked

Does this replace the DMV bill of sale?
Not entirely — your state's DMV form is still required for title transfer. But Authryn captures the agreed-upon terms (price, mileage, condition, as-is clause, etc.) with phone-verified signatures, which is far stronger evidence than the basic DMV form alone.
Can I include the 'sold as-is' language?
Yes. Put it in the description: 'Sold as-is, no warranty, mileage 87,453 verified.' Both parties phone-verify and sign. If they dispute later, you have their signed agreement.
What about VIN, mileage, plates?
Include all of it in the description. The receipt captures the full text of what you both agreed to and locks it cryptographically — nobody can edit it after signing.
Does this work for cash deals?
Especially for cash deals. A signed Authryn receipt is the closest thing to a Venmo paper trail you'll get for a cash car sale.
How much does it cost?
$1 per receipt — and your first one is free. For a multi-thousand-dollar car sale, it's the cheapest insurance you'll buy.

Ready to sell on used car without fear?

Your first receipt is free. No card, no commitment, no app. Just trust — built in 30 seconds.

Get my free receipt