The act of paying more than the amount due (or the excess amount itself; legally often called overpaid funds).
給料の計算ミスで先月は過払いが発生したので、会社に相談した。
Because of a payroll calculation error there was an overpayment last month, so I consulted the company.
消費者ローンの過払いが問題になり、過払い金返還請求をする人が増えた。
Overpayments on consumer loans became an issue, and the number of people claiming repayment of overpaid funds increased.
店員にお釣りを渡されていないか確認して、過払いがないかチェックしてください。
Check whether the clerk gave you change and make sure there was no overpayment.
会計で過払いが発覚したため、翌月の支払いで調整された。
An overpayment was discovered in accounting, so it was adjusted in the following month's payment.