From the IRS website directly:
- Contact your employer first. Ask your employer – or former employer – to send your W-2 if it has not already been sent. Make sure your employer has your correct address.
- Contact the IRS. After February 14, you may call the IRS at 800-829-1040 if you have not yet received your W-2. Be prepared to provide your name, address, Social Security number and phone number. You should also have the following information when you call:
• Your employer’s name, address and phone number;
• Your employment dates; and
• An estimate of your wages and federal income tax withheld in 2012, based upon your final pay stub or leave-and-earnings statement, if available.
https://www.irs.gov/newsroom/missing-your-w2-here-is-what-to-do
