uthrynStop getting scammed
in private deals.
When you sell that phone, car, or freelance gig, both parties sign a phone-verified, tamper-proof receipt in under 60 seconds. No more “he said, she said.”
What happens when there is
no proof of the deal?
Every day, thousands of honest people lose money, time, and sleep over transactions they can't prove happened the way they remember.
“I never got the item”
Buyer disappears after pickup, then files a chargeback or accuses you of fraud. Without proof of the handover, you lose both ways.
“You damaged it”
Seller claims the item was perfect when sold. Now they want a refund or threaten to leave bad reviews. Your word against theirs.
“That's not what we agreed”
Price suddenly changes. Items get swapped. Promises evaporate. Texts can be deleted. Screenshots can be edited. There is no neutral record.
There is a 50-cent solution to this. Both parties verify their phone, both sign the same receipt, and the record can't be edited. Done.
See how it worksHow It Works
Three steps. Under a minute. Done forever.
Create & Sign
Enter the transaction details — what, for how much, with whom. Sign it. A unique QR code is generated.
Other Party Verifies
They scan the QR or open the link, enter their phone number, and receive an SMS code. Real number, real person.
Both Sides Locked In
Both signatures are cryptographically bound. The receipt is tamper-proof and verifiable by anyone, anywhere.
Where people use Authryn
Anywhere strangers exchange money for something. If it's worth more than $20, it's worth a receipt.
Facebook Marketplace
Selling a phone, console, or furniture? Lock in the deal before they show up.
Craigslist & OfferUp
Meeting a stranger for cash? Add a layer of proof before money changes hands.
Freelance Deposits
Designers, developers, photographers — get paid upfront with proof both sides agreed.
Used Cars & Vehicles
Private vehicle sales with cash. Document the transfer with two-party signatures.
Concert & Event Tickets
Reselling a Taylor Swift ticket? Prove the buyer agreed to the price before sending.
Sublets & Deposits
Subletting a room or holding a deposit? Both parties sign so nobody can deny it later.
...and anywhere else two people need a paper trail without the actual paper.
See an actual
Authryn receipt
Every receipt has a unique reference ID, transaction details, timestamps, and phone-verified signatures from both parties. Anyone with the reference ID can verify it's real.
Unique Reference ID
Human-readable format: AUTH-XXXX-XXXX
Phone-Verified Signatures
Both parties verified via SMS. VoIP numbers blocked.
SHA-256 Integrity Hash
Standard cryptography. Same tech as your bank uses.
Complete Audit Trail
Every action timestamped. Nothing can be altered after signing.
uthrynCompare your options
Everyone has a phone. Not everyone has proof.
| Method | Both Signed | Phone Verified | Tamper-Proof | 3rd-Party Verifiable |
|---|---|---|---|---|
| Verbal handshake | ||||
| Text message | ||||
| Screenshot of chat | ||||
| Email confirmation | ||||
| Hand-written receipt | ||||
| Authryn receipt |
Only an Authryn receipt checks every box. And it costs less than a stamp.
Real situations.
Real protection.
How people are using Authryn to take the “he said, she said” out of private deals.
“Buyer tried to claim he never got the laptop after picking it up. I pulled up the Authryn receipt with his signed confirmation — argument over in 30 seconds.”
“I now require an Authryn receipt before any project starts. Clients respect it, and I have proof of what was agreed if anything goes sideways.”
“Way better than a hand-written bill of sale. Both of us got it on our phones in under a minute and the buyer felt safer handing over cash.”
Why choose Authryn
Built for trust, transparency, and peace of mind.
Prevent Disputes
Both parties sign the same record. Clear proof of what was agreed eliminates misunderstandings and protects everyone.
Reduce Fraud
Phone verification ensures real people on both sides. VoIP and virtual numbers are blocked to maintain security.
Build Lasting Trust
Show buyers or sellers you're serious about transparency. Authenticated receipts signal professionalism and accountability.
Complete Transparency
Every action is timestamped. Both parties can verify the integrity of the record at any time using the reference ID.
You probably want to know
Honest answers to the questions everyone asks before signing up.
Screenshots can be faked in 30 seconds with any photo editor. An Authryn receipt is phone-verified on both sides, cryptographically hashed with SHA-256, and stored on our servers with a unique reference ID. Anyone in the world can verify it's real — a screenshot can't do that.
Authryn is not a legal contract by itself, and we don't pretend to be. What we provide is strong evidence of agreement — both parties verified their phone via SMS, agreed to the same details, and digitally signed. That kind of proof holds up in small-claims court, with payment processors, and in disputes far better than a text message.
Then you have your answer before you hand over the item or the money. If someone won't put their real phone number on a $500 transaction, that's a red flag. Honest buyers and sellers have no problem with a 30-second verification.
Under 60 seconds. You enter the details, the other person scans the QR code or opens the link, both of you receive an SMS code, and you're done. Faster than writing a hand-signed receipt.
No. Your first receipt is completely free after you sign up — no credit card required. Try it on a real transaction, and only pay $0.50 per receipt after that. Failed receipts are refunded automatically.
Yes. Phone numbers are only used for verification and are masked on every public receipt (e.g. •••-•••-4521). We never sell, share, or advertise to your number, and we block VoIP / virtual numbers to keep things real.
No. We're not a payment processor, escrow service, or bank. You handle the actual payment however you normally do — cash, Zelle, Venmo, bank transfer. We just create the proof that both parties agreed to the transaction.
Yes. As long as both parties have a real mobile number that can receive SMS, Authryn works. Receipts support multiple currencies.
Still have questions?
Contact SupportStart free. Stay fair.
No subscription. No hidden fees. Pay only when you use it.
No credit card required to sign up
Your next deal could be the one.
Don't learn this lesson the expensive way. Create your first authenticated receipt — on us.
Get My Free ReceiptTakes 60 seconds. No credit card. No commitment.