"Bonus, Extra, Overtime pay are usually taxed at the 25% to 28% tax rate when paid to the employee. When you file at year end everything is figured on the tax bracket you are in. So you give extra to the IRS up front and then get the extra back when you file your taxes, unless of course your in the high tax bracket."
Thansk to all for the responses. Seems my usually reliable source missed the mark this time.