When you generate an invoice for a product or service with OpenNode, your customer may accidentally underpay the invoice. This can occur if the payee doesn't include a few extra sats to cover the network fees for an on-chain Bitcoin transaction. If an invoice is underpaid, then we will hold it for you and email you, asking how you'd like to proceed. You can either reject the payment or send it through depending if you're comfortable with the amount that was underpaid.
OpenNode offers an underpaid threshold feature that allows you to set a limit on what you are willing or not willing to accept for an underpaid invoice. Learn more about our underpaid threshold feature here.