Can you file taxes without one employer's W-2 if they have not sent it and what are your legal responsibilities?

First - Not receiving these, or any form I can think of - is NEVER an acceptable excuse for not acting/reporting as if you had. Yes, in fact, it becomes your obligation to do more. Especially with a W-2, which tracks withholding, FICA, Unemp. Insur, Work comp, etc., you may have made (or done on your behalf) and would want to be credited with, you should absolutely want to resolve it. If you do not receive your Form W-2, Form 1099-R, Form 1099-INT, or Form 1099-MISC by January 31st , or your information is incorrect, contact your employer/payer first. Many times they have been returned in the mail, for any number of reasons, or a substitute is available easily, even on line. Keep records of this contact - preferably by sending a certified letter reiterating what was said. If you do not receive the missing or corrected form by February 15th from your employer/payer, you may call the IRS at 1-800-829-1040 for assistance. You must provide your name, address (including zip code), phone number, Social Security Number, dates of employment, your employer/payer's name, address (including zip code), and phone number. With your information, the IRS will contact the employer/payer for you and request the missing form. IRS will also send you a Form 4852 (PDF) (Substitute for Form W-2 or Form 1099-R). If you do not receive the missing form in sufficient time to file your tax return timely, you may use the --***--- Form 4852 ---***---. If you receive the missing or corrected Form W-2 or Form 1099 after you file your return and a correction is needed, use Form 1040X (PDF) (Amended U.S. Individual Income Tax Return).