noun, noun or participle which takes 'suru', transitive verb
overpayment; excess payment
Refers to paying more than the required amount, often used in tax, fee, or billing contexts. Can be used as a noun or as a suru-verb (過納する).
税金を過納してしまったので、還付を申請した。
I overpaid my taxes, so I applied for a refund.
過
The overpaid amount will be refunded at a later date.