For years, the deadline has been 2/28 to file W-2s. In a seminar last week on tax changes, the presenter made a point that this had been changed to 1/31. IRS made the change to combat the rash of identity theft (IRS will have W-2 and 1099 information to match to).

Here are the SSA and IRS links:

https://www.ssa.gov/employer/filingDeadlines.htm

https://www.irs.gov/uac/newsroom/reminder-employers-face-new-jan-31-w2-filing-deadline-some-refunds-delayed-until-feb-15

https://www.irs.gov/tax-professionals/e-file-providers-partners/filing-information-returns-electronically-fire

Also note that the penalties for non-filing of information returns (in particular intentional disregard) have increased substantially:

https://www.irs.gov/government-entities/federal-state-local-governments/increase-in-information-return-penalties-2