it depends. the basic rule(eg for self-employed) is that you get paid then owe a lump sum on april 15th. but most employers withold (estimated) taxes for the irs by default. if they over estimate, the government issues a refund. but you avoid witholdings with claims on a standard employment tax form that everyone fills out unless you get paid under the table. but if you claim, you get more in your paycheck but owe more in april.
United States