滞纳金英文是Late fee，或许用 Overdue Payment 会更加接近一些，因为滞纳金大多时候是指针对不按纳税期限缴纳税款或者不按还款期限归还贷款，按滞纳天数加收滞纳款项一定比例的金额，它是税务机关或者债权人对逾期当事人给予经济制裁的一种措施。
What is a late fee(滞纳金)？
1.A late fee, also known asa late fine or a past due fee, is a charge levied against a client by a company or organization for not paying a bill or returning a rented or borrowed item by its due date. Its use is most commonly associated with businesses like creditors, video rental outlets and libraries. Late fees are generally caLCulated on a per day, per item basis.
2.A late fee, also known as an overdue fine, late fine, or past due fee, is a charge fined against a client by a company or organization for not paying a bill or returning a rented or borrowed item by its due date.
3.A fee charged when a payment is not received on time. Some common bills which almost always have a late fee policy are credit card payments, mortgage and student loan payments, and car loan payments.