Employers - Federal unemployment tax. File Form 940 for 2008. If your undeposited tax is $500 or less, you can either pay it with your return or deposit it. If it is more than $500, you must deposit it. However, if you already deposited the tax for the year in full and on time, you have until February 10 to file the return.

Employers - Social security, Medicare, and withheld income tax. File Form 941 for the fourth quarter of 2008. Deposit any undeposited tax. (If your tax liability is less than $2,500, you can pay it in full with a timely filed return.) If you deposited the tax for the quarter in full and on time, you have until February 10 to file the return.

Employers - Nonpayroll taxes. File Form 945 to report income tax withheld for 2008 on all nonpayroll items, including backup withholding and withholding on pensions, annuities, IRAs, gambling winnings and payments of Indian gaming profits to tribal members. Deposit any undeposited tax. (If your tax liability is less than $2,500, you can pay it in full with a timely filed return.) If you deposited the tax for the year in full and on time, you have until February 10 to file the return.

Employers - Give your employees their copies of Form W-2 for 2008. If an employee agreed to receive Form W-2 electronically, post it on a website accessible to the employee and notify the employee of the posting by February 2nd.

Individuals - who must make estimated tax payments. If you did not pay your last installment of estimated tax by January 15, you may choose (but are not required) to file your income tax return (Form 1040) for 2008. Filing your return and paying any tax due by February 2, 2009 prevents any penalty for late payment fo last installment.

Businesses - Give annual information statements to recipients of 1099 payments made during 2008.

Payers of Gambling Winnings - If you either paid reportable gambling winnings or withheld income tax from gambling winnings, give the winners their copies of Form W-2G.

Certain Small Employers - File Form 944 to report social security and Medicare taxes and withheld income tax for 2008. Deposit or pay any undeposited tax under the accuracy of deposit rules. If your tax liability is $2,500 or more from 2008 but less than $2,500 for the fourth quarter, deposit any undeposited tax or pay it in full with a timely filed return.

Employers - Federal unemployment tax. File Form 940 for 2008. This due date applies only if you deposited the tax for the year in full and on time.

Employers - Nonpayroll taxes. File Form 945 to report income tax withheld for 2008 on all nonpayroll items. This due date applies only if you deposited the tax for the year in full and on time.

Employees - who work for tips. If you received $20 or more in tips during January, report them to your employer. You can use Form 4070 Employee's Report of Tips to Employer.

Employers - Social security, Medicare and withheld income tax. If the monthly deposit rule applies, deposit the tax for payments in January.

Employers - Nonpayroll withholding. If the monthly deposit rule applies, deposit the tax for payments in January.

Individuals - If you claimed exemption from income tax withholding last year on the Form W-4 you gave your employer, you must file a new Form W-4 by this date to continue your exemption for another year.

Employers - Begin withholding income tax from the pay of any employee who claimed exemption from withholding in 2008, but did not give you a new Form W-4 to continue the exemption this year.