noun
A formal term for a required payment or contribution, often used in official, legal, or tax contexts.
国民年金の納付金は毎月支払う必要がある。
National pension contributions must be paid every month.
この書類には納付金
The amount of the levy is clearly stated in this document.
支払い is a general term for payment, whereas 納付金 is a formal, often obligatory payment to an authority.
Compound of 納付 (payment, contribution) and 金 (money).