January 15, 2011

Deadline to pay your fourth quarter estimated tax payment. However, you can skip this estimated payment without penalty if you file your return and pay your balance in full by January 31, 2011.

January 31, 2011

Deadline for employers to mail out Form W-2 and for businesses to furnish Form 1099 statements reporting, among other things, non-employee compensation, bank interest, dividends, and distributions from a retirement plan.

Deadline for self-employed individuals to file and to pay their tax and avoid an penalty for not making your 4th quarter estimated tax payment.

February 16, 2011

Deadline for employees who claim exemption from withholding to file a new Form W-4 with their employers.

Deadline for financial institutions to mail out Form 1099-B, relating to sales of stock, bonds or mutual funds through a brokerage account, and Form 1099-S, relating to real estate transactions.

March 15, 2011

Deadline for corporate tax returns (Forms 1120, 1120A, and 1120S), or to request automatic 6-month extension of time to file (Form 7004).

Final deadline to file an amended corporate tax return (Form 1120X) for tax year 2007 and still claim a tax refund.