o‧ver‧pay past tense and past participle overpaid
to pay someone more money than they deserve [≠ underpay]:
Most big companies continue to overpay their top executives.
2 [intransitive and transitive]
to pay too much money for something [≠ underpay]:
Try to recover any tax you have overpaid.
—overpayment noun [uncountable and countable]