January 17—Individual taxpayers’ final 2011 4th quarter estimated tax payment is due unless Form 1040 is filed by January 31, 2012, and any tax due is paid with the return.

January 31—Give your employees their copies of Form W-2 for 2011. If an employee agreed to receive Form W-2 electronically, have it posted on the website and notify the employee.

—Give annual information statements to recipients of certain payments you made during 2011. You can use the appropriate version of Form 1099 or other information return. Form 1099 can be filed electronically with the consent of the recipient.

February 28—The government’s copy of Form 1099 series returns (along with the appropriate transmittal form) should be sent in by today. However, if these forms will be filed electronically, the due date is extended to April 2.

February 29—The government’s copy of Form W-2 series returns (along with the appropriate transmittal form) should be sent in by today. However, if these forms will be filed electronically, the due date is extended to April 2.

—File Form W-3 (Transmittal of Wage and Tax Statements) along with Copy A of all the Forms W-2 you issued for 2011. If you file Forms W-2 electronically, your due date will be extended to April 2.

March 15—2011 income tax returns must be filed or extended for calendar-year corporations. If the return is not extended, this is also the last day for calendar-year corporations to make 2011 contributions to pension and profit-sharing plans.