Last updated 14 September 2026
Security
Paisa sits close to your money without ever touching it. Here is how that is arranged, and what to check before you pay anyone.
Your money never passes through us
UPI to UPI, their bank to yours. We hold no funds, take no cut, and are never in the middle of a transfer.
We never ask for a PIN or OTP
There is no field for one anywhere in the product. Anything asking you for one is not us.
Access is enforced at the database
Every read and write is checked against your group membership by the database itself — not just hidden in the interface.
The one check that matters
Before confirming any UPI payment, check that your own banking app shows the name you expect. That check is done by your bank against the real account holder — it is the one thing no impersonator can fake, and it protects you whether or not the link came from us.
How access works
- Authorisation lives in the database, so a bug in the interface cannot expose someone else's ledger. Every query is filtered by what you are actually a member of.
- Personal expenses and your own preferences are readable by you alone. Group data is readable by that group's members.
- Editing group settings, membership and permissions is restricted to owners; adding expenses is restricted to editors.
- The privileged server key is never sent to the browser. It is used only for public share pages, which are deliberately scoped to a single link.
Share links
A share link is unguessable, but anyone holding it can open it — treat one like a password rather than a secret. You can give it an expiry, protect it with a password, and revoke it the moment you no longer want it live.
On a settle-up link, marking a payment as sent only ever files a claim for the person owed to confirm. It cannot move a balance on its own, which is what makes the link safe to pass around a group chat.
Your data in transit and at rest
- Everything is served over HTTPS.
- Data and uploaded files are stored with our infrastructure provider's encryption at rest.
- Share-link passwords are stored as salted, computationally expensive hashes — never as text we could read back.
- Uploaded receipts and settlement proofs are kept in access-controlled buckets, not on a public URL.
Reporting a problem
If you think you have found a vulnerability, please tell us before telling anyone else, and give us a reasonable window to fix it: get in touch. We would much rather hear it from you.