surcharge
n. countablen. an extra amount of money that you must pay on top of the usual price. It is often added for special services or because of a price increase in things like fuel.
n. an additional charge, tax, or cost added to the base price of a good or service. Often applied as a temporary measure to offset specific cost fluctuations or to penalise certain payment methods.
The airline added a fuel surcharge to the ticket price.
Many restaurants now include a small surcharge for customers who choose to pay with a credit card instead of cash.
To mitigate the impact of rising energy costs, the shipping company implemented a variable surcharge that fluctuates according to the monthly global price of crude oil.
From Middle French surcharge, from Old French. By surface analysis, sur- + charge. Doublet of supercharge.
Commonly takes the preposition 'on' (a surcharge on imports) or 'for' (a surcharge for late payment).