Can you legally file taxes with your last check stub?

Absolutely. If you didn't even have a last pay stub, or a W-2, you still legally HAVE to file your income tax. When you do get the information on say a W-2, if it doesn't match what you filed, you will have to amend and correct your filing. However, you should wait for several reasons: The return likely won't be processed until the employer has filed all his reports (generally due by 01/31), and they can be matched to what your claiming. The information on the W-2 may have year end adjustments, additions, etc that don't match your last stub. Tha will delay your retuirn for a long time while the dicrepency is resolved - and rthen you will have to file an amended return. Some information you need to report, certain employer ID#s etc may not be available on a pay stub. If it is available, you are really required to use it or explain why you didn't have one, using another complex form. You want to use the best information available and follow the established process as best you can, or expect problems!