January 31
Employers must furnish W-2 statements to employees. 1099 information statements must be furnished by payers. (Deadline for 1099B and consolidated statements is February 15.)

January 31
Employers must file 2011 federal unemployment tax returns and pay any tax due.

February 29
Payers must file information returns (such as 1099s) with the IRS.*

Employers must send W-2 copies to the Social Security Administration.*

March 1
Farmers and fishermen who did not make 2011 estimated tax payments must file 2011 tax returns and pay taxes in full.

*April 2 if filing electronically.