nuisance tax

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A small excise tax levied on separate purchases and collected directly from the purchaser.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A tax imposed as a percentage of the selling price of goods or services, payable by the customer and transmitted by the seller to the taxing authority.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a tax based on the cost of the item purchased and collected directly from the buyer