What you've paid on time, finally provable.
Take your record with you to another city, another bank, another landlord. No editable documents, no letters nobody can verify.
Rent for September 2024, €241.40.
Invoice checked against the Spanish Tax Agency and recorded on Solana, without revealing the amount to anyone who doesn't have the link.
You pay as usual
Your agency issues the rent invoice with its VeriFactu QR code.
You generate the proof
You paste the QR link and we check it with the Tax Agency.
It's recorded on Solana
Once, with no duplicates and none of your personal data in plain text.
Anyone you choose checks it
With a link, without asking anyone's permission.
Infrastructure, not an app
This site is only the demo client. The value is in three layers anyone can use without asking us.
Open rules on Solana
Proofs follow a public schema on the Solana Attestation Service. What counts as valid, and that an invoice can't be registered twice, is enforced by code, not by our servers.
A record that grows
Every new proof makes the whole set more useful for whoever needs to verify: agencies, banks, insurers.
An open SDK
Any platform can issue or check proofs by integrating it, without going through this site.
We don't promise perfect authenticity
Each proof states where it comes from and how far it can be trusted.
VeriFactu invoice (AEAT)
Available in this pilotChecked against the Spanish Tax Agency's public invoice verification service.
Stated by the issuer
Available in this pilotThe agency publishes the payment from its own system, with no external check. It's how an agency would publish all its tenants' payments at once, and it's labelled as such.
Portal with a session (zkTLS, Reclaim)
Coming soonWill rely on Reclaim's validators, which are being decentralised.
An issuer can withdraw a proof it issued, but the withdrawal stays publicly visible on Solana: it can't be done in secret.
Frequently asked questions
What exactly does a proof show?
That the Spanish Tax Agency confirms the invoice exists, and that the issuer states it was paid. With the full link, it also shows the amount and date.
What does "stated by the issuer" mean?
That the agency published the payment from its own system, with no invoice checked by the Tax Agency. It carries less assurance, and every proof says so.
What is stored on Solana?
Only a fingerprint of the invoice, its month and who issued the proof. Nobody can work out the amount or the tax ID from the fingerprint.
What if I lose the link?
The proof still exists and anyone can check it with its identifier, but the amount can no longer be shown. We don't keep a copy.
Why does it say Devnet?
This pilot runs on Solana's test network, which costs nothing. All the data is fictitious, including the issuing agency.
Do I need a wallet?
No. You can link the proof to your wallet if you want to carry it with you, but checking a proof never needs one.