If you have state withholding for more than eight states, or more than eight local withholdings, you will need to enter the additional state and or local withholdings on a separate Form W-2 Wage and Tax Statement. Be sure to select the state and locality from the drop-downs for Boxes 15 and 20 again.

You would not be able to file electronically, rather you would need to file a paper return.

Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.