Overpayments and refunds
Crypto payments do not always arrive as invoiced. A customer can send more than asked, less than asked, or send again after the payment has settled. This page describes what the system does in each case, so you can predict it rather than discover it.
Overpayment
Section titled “Overpayment”If more arrives than the invoice, you are paid the invoice amount in full and the excess is handled separately. Your settlement is unaffected by the customer overpaying.
The excess is not automatically returned to the address it came from. Many customers pay from an exchange account, where the sending address is a shared hot wallet, and returning funds there would mean the customer never sees them. So the excess is held and the customer is asked to supply an address for it.
A flat fee of $0.50 is deducted from any refund to cover the cost of sending it.
If the excess is smaller than $0.50, no refund is made. Moving it would cost more than the amount itself.
Underpayment
Section titled “Underpayment”If less arrives than the invoice, the payment does not complete. The customer can top up to the full amount, and the payment completes when the total is reached.
If the payment expires without reaching the invoice amount, what arrived is refunded, less the same flat fee. Where the amount that arrived is smaller than the fee, no refund is made, for the same reason as above.
Paying twice
Section titled “Paying twice”Funds arriving at a deposit address after the payment has already settled are treated as an extra deposit and refunded on the same terms.
Refunding a completed order
Section titled “Refunding a completed order”A customer paid $50, the order settled, and now they want their money back.
There is no API for this. Once a payment settles, the money is in your wallet, not ours. There is nothing for us to return, because we are not holding it. You send it back yourself, from that wallet, the same way you would send any other payment.
This is the part that differs from card processing. A card processor holds funds and can reverse a charge on your instruction. A confirmed on-chain payment cannot be reversed by anyone, so returning money to a customer is a new payment that you make.
So what are the refunds on this page?
Section titled “So what are the refunds on this page?”They are the opposite case: money Stablezact is still holding because the payment did not land cleanly. Excess from an overpayment, an expired underpayment, a duplicate deposit. Those we can return, and we do it automatically. You do not request them and there is nothing to call.
| Situation | Who holds the money | Who returns it |
|---|---|---|
| Overpaid, excess left over | Stablezact | Stablezact, automatically |
| Underpaid and expired | Stablezact | Stablezact, automatically |
| Paid again after settling | Stablezact | Stablezact, automatically |
| Customer wants a settled order refunded | you | you |
Cross-chain payments
Section titled “Cross-chain payments”Payments that arrive on a different chain from the one invoiced go through a bridge. Bridges have their own minimums, and a refund below one may be declined by the bridge and require manual handling. Amounts of a few cents are the usual cause.
Summary
Section titled “Summary”| Situation | What happens |
|---|---|
| Overpaid | invoice settles in full; excess held, customer asked for an address |
| Overpaid by less than $0.50 | no refund; the amount is below the cost of sending it |
| Underpaid | payment stays open; customer can top up |
| Underpaid and expired | refunded less the $0.50 fee |
| Underpaid, and less than the fee arrived | no refund |
| Paid again after settling | treated as an extra deposit and refunded |