Short answer: the only reliable proof that money arrived is the money itself — your bank balance — or a system that checks the slip against bank data. Looking at a slip image is no longer enough: AI can now produce fake slips that are almost impossible to tell apart. And even a genuine slip can belong to someone else's transfer, or be an old one sent again. The table compares five ways to check, what each catches, how long it takes and who it suits.
Five ways to check a slip, compared
| Method | Catches a fake slip? | Confirms it was paid to you, and not reused? | Time per slip | Suits |
|---|---|---|---|---|
| 1. Look at the slip image | Unreliable · AI-made fakes are hard to spot | No | Seconds | Never on its own |
| 2. Scan the slip's QR code with a banking app | Yes · a fake QR won't verify | You still check recipient, amount and reuse yourself | About 30 seconds | A few orders a day |
| 3. Check money-in in your banking app or the bank's alerts | Yes · it's the real money | Shows money arrived, but you match it to orders by hand · hard when amounts repeat | Half a minute to minutes | Small shops |
| 4. A slip-verification API (e.g. EasySlip) | Yes · checked against bank data | Returns recipient and amount; matching orders and blocking reuse is yours to build | Seconds (once built) | Shops with developers |
| 5. A back office with slip checking built in | Yes · checked against bank data | Yes · recipient, exact amount and reuse checked per order (varies by tool) | Seconds | Shops taking many chat orders a day |
Why scanning the QR isn't enough on its own
The QR code on a slip proves the transfer exists in the banking system. It doesn't prove it was paid to your shop, for this order. So scammers use real slips instead: one paid to someone else, an old slip already sent to you, or a slip for less than the agreed amount.
Before you pack, check all four:
- Paid to your account · the recipient name or PromptPay matches yours
- Exact amount · the order total including shipping, no more, no less
- Transferred after you sent the amount · a slip older than your message is suspicious
- Never used for another order · its reference number hasn't come in before
Number 4 is the hardest by hand — you'd have to remember every reference number you've received. It's why shops with many orders move to automatic checking.
How automatic slip checking works
- Read the transaction reference from the slip's QR code
- Ask the bank for that transaction, through a slip-verification provider
- Compare recipient, amount and time with the order being paid
- Check the reference hasn't been used for another order
- All pass: the order is ready for the shop to confirm with one tap · Any fail: the reason in plain words, like "amount doesn't match" or "this slip was already used"
A good system never marks an order paid when it isn't sure. If the bank is slow or the check fails, the order stays "awaiting payment" and the shop is told. Calling an order paid when the money isn't there is worse than a slow check.
How Nava checks slips
Nava is a back office for Thai shops that sell in LINE chat. It checks each slip against bank data through EasySlip — paid to the shop's PromptPay, the exact amount, and never used before — then the shop confirms with one tap. Money goes straight to the shop's own PromptPay; Nava never holds funds and charges nothing per slip. Nava is in a private pilot with Thai sellers and opens to everyone in February 2027.
Every slip checked with the bank · paid straight to your account
Join the Nava waitlist →