Overpayments and Underpayments

Changes to an order after payment (such as adding, removing, or substituting items) may cause the total amount due to increase or decrease. This can result in overpayments (the customer has paid more than the final total) or underpayments (the customer has paid less than the final total).

Common scenarios include:

• Removing products — decreases the total, potentially creating an overpayment

• Adding products — increases the total, resulting in an underpayment

• Substituting products — may increase or decrease the total, depending on the price differences

• Applying or removing discounts — changes the total due