Taxes will depend on how new company wants to issue bonus as they are who decides bonus tax structure
Bonuses Are Considered “Supplemental Wages”.
Bonus Taxes
If you read the tax code, you will notice that the Internal Revenue Service goes to great lengths to categorize different types of income and treat them differently. Bonuses are another example of this. In the eyes of the IRS, bonuses are typically categorized as “supplemental wages.” As a*University of Minnesota*summary explains:
“The IRS defines supplemental wages as compensation paid in addition to the employee’s regular wages that includes, but is not limited to, severance or dismissal pay, vacation pay, back pay, bonuses, moving expenses, overtime, taxable fringe benefits, and commissions.”
As such, bonuses (like other supplemental wages) are treated differently than ordinary wage or salary income. There are two ways of taxing bonuses: the percentage method and the aggregate method. Which method gets applied to your bonus? Let’s find out.
The Percentage Method
The IRS specifies a flat “supplemental rate” of 25%, meaning that any supplemental wages (including bonuses) should be taxed in that amount. If you receive a $5,000 bonus, under this rule, $1,250 (25% of $5,000) goes straight to the IRS. Using this approach, the amount of your bonus – whatever it is – is “singled out” from the rest of your income and taxed directly. Employers frequently choose the percentage method because it’s easy and mindless to tax the entire bonus at a uniform rate.
In most cases, this is ideal from your standpoint as the bonus receiver and taxpayer, too. The aggregate method (described below), in addition to being more time-consuming and laborious for employers, can take a bigger tax bite out of your bonus payments.
The Aggregate Method
Unlike the much simpler percentage method, the aggregate method is when your employer adds the amount of your bonus (say, $5,000) to your most recent regular paycheck. Then, they determine the normal withholding amount based on IRS withholding tables for the sum of both amounts, subtract what was already withheld from your last paycheck, and withhold the rest from the bonus amount.
The problem with this approach is that instead of being taxed at a flat 25% – and having that 25% rate apply only to the bonus amount – you get taxed at what is almost certainly a higher rate on thecombined*amount of your normal pay*and*the bonus. The result: a higher overall tax obligation for the same amount of income.
Here is a*free bonus calculator*based on the aggregate method. Use it to determine your bonus-related tax obligation should your employer choose this approach.
http://blog.turbotax.intuit.com/2013/11/11/how-bonuses-are-taxed-calculator/
http://blog.turbotax.intuit.com/2011/12/09/bonus-time-how-bonuses-are-taxed-and-treated-by-the-irs/