A customer’s transfer lands short by a few baht, or over by a lot, and chat answers it wrong half the time — ignore it, argue, or ship anyway. The fix is a short decision rule built around why these mismatches actually happen, plus the exact buttons 1CS’s bill flow already gives your team to settle it before the parcel leaves.
Why the number on the slip doesn’t match the bill
Thailand’s PromptPay QR codes come in two forms, and which one a customer used decides whether a typo was even possible. A static QR — printed on a till sticker, or pasted once into a chat — carries no amount at all, so the customer types the figure in themselves every time; a dynamic QR, generated fresh for one purchase, has the total already built in (Bank of Thailand, “The Knowledge: PromptPay”).
A bill sent from 1CS shows the customer the exact total as text next to your shop’s saved payment account — one bank account, PromptPay number, or QR image, not a fresh QR generated for that order. So the step most mismatches come from — typing an amount into a banking app — still happens after the customer reads the total off your bill, which is exactly where a digit gets dropped or doubled.
Decide before you reply
A mismatch falls into three buckets, and each needs a different reply — our own recommended default below, not a published benchmark:
- Short. The transfer is real but smaller than the bill. Ask for the difference and hold the item; don’t pack until it clears.
- Over. The transfer is bigger than the bill. Hold the surplus and tell the customer how you’ll send it back — this is your shop returning its own money, not a bank reversal, so it only needs your team’s confirmation, not anyone else’s consent.
- Nothing arrives at all. The customer has a slip, but no transfer reaches your account — usually a mistyped or mis-scanned PromptPay number. That recovery is between the customer and their own bank, not something your shop can act on: a bank can only reverse a misdirected transfer with the receiving account holder’s consent, and the standard first step is the sender contacting their own bank with the slip as evidence (Krungsri, “โอนเงินผิดบัญชี”). Point the customer there rather than promising to track down money that never reached you.
ตั้งค่าใน 1CS
1CS’s bill flow (เมนู ธุรกิจ > ขายสินค้า) gives this decision a fixed home instead of a comment buried in chat history. After a customer opens the bill link and taps แจ้งว่าชำระเงินแล้ว (“report as paid,” with an optional note), the bill moves into a queue at ธุรกิจ > ขายสินค้า > บิล, filterable by “ต้องจัดการ” (needs action). Your team checks the amount against the bill, then taps ยืนยันการโอน (confirm transfer) if it matches, or ตีกลับสลิป (reject slip) if it doesn’t — which reopens the bill for the customer to fix instead of leaving the gap for someone to notice later.
The walkthrough for selling and billing in chat (in Thai) covers setting up the catalog and payment account first, screen by screen.
A message for the gap, not a guess
Two short templates — one for each direction a mismatch usually goes:
Hi [customer name], we received [amount received] for order [order number], but the total is [bill amount] — a difference of [difference]. Could you send the remaining [difference] to the same account by [deadline, e.g. today 6pm]? We’ll hold your item until then.
Hi [customer name], the transfer for order [order number] came in at [amount received], which is [difference] more than the bill total. Let us know the account you’d like that back on and we’ll send [difference] today.
Keep both specific to the order and the number, never “your payment” — a vague message gets a vague reply, and a vague reply is how a short transfer turns into a packed order with the difference quietly written off.
None of this replaces checking that a transfer is genuine in the first place, which is a separate five-point check worth running before the amount question even comes up. And a mismatch is one more reason, alongside a first-time customer or an unusually large order, to hold a conversation for a human before anything ships.
