When issuing a duplicate W-2: Type “REISSUED STATEMENT” in the upper right-hand corner on all W-2 copies. It is acceptable to use a copy of the employer’s copy.
Sending W-2s to former employees. Photocopy the envelope in a way that shows the recipient's address, and write on the duplicate copy the date you mailed it.
Handling returned W-2s. If you mail W-2s, keep a returned one in the envelope. If you hear from the employee, put this envelope in another envelope and mail it to the corrected address. If you don’t hear from the employee, keep it for at least 4 years as proof that it was mailed by the deadline.
Alternative: As we reported to our members in June, IRS final regs offer an easy new way to retain returned W-2s. You can meet regulatory requirements by scanning W-2 copies B and C, then shredding the originals.
Also scan the envelope in which the W-2 was mailed (because the postmark and address are proof that you mailed it and when). Scanning has a privacy benefit: W-2s with names, addresses and SSNs are not accessible simply by opening a drawer. Be sure your electronic storage is secure. [IRS Rev. Proc. 97-22, 1997-3 I.R.B. 9, Guidance on Electronic Records]