Although it is possible to prepare a preliminary tax return based on your final pay stub for the year, your pay stub is not the official IRS-recognized document for your income. Taxpayers should not use their final pay stub, a similar substitute form, or Form 4852 to file their income tax return prior to the receipt of an employer-provided Form W-2.

The amount of gross wages showing on the final pay stub may not match what your employer will enter in Form W-2, Box 1 Wages, tips, other comp due to any of the following reasons:

1. Tax deferred contributions (i.e. 401k, 403b, etc.)
2. Pre-tax health, dental or vision insurance premiums
3. Dependent care or medical reimbursement account deductions made from your pay during the year
4. Premium amounts for the value of group life insurance coverage in excess of $50,000
5. Various other taxable benefits that the employer must add to the final W-2 Form

If you receive a Form W-2 or Form W-2C after your return is filed, and the information differs from that reported on your return, you must amend your return by filing Form 1040X Amended U.S. Individual Income Tax Return.