> How does your employer know what "the appropriate amount of taxes" is?
It's an approximation based on your revenue (and they know how much they'll pay you). At end-year everything is tallied all proper and as taxpayer you either have to pay the missing bits (if you have extra revenues which weren't accounted for by your salary) or you receive a wire transfer from the state (if you had deductions which weren't taken in account e.g. dependents or whatever).
It's an approximation based on your revenue (and they know how much they'll pay you). At end-year everything is tallied all proper and as taxpayer you either have to pay the missing bits (if you have extra revenues which weren't accounted for by your salary) or you receive a wire transfer from the state (if you had deductions which weren't taken in account e.g. dependents or whatever).