April 12
Employees who work for tips
If you received $20 or more in tips during March, report them to your employer. You can use Form 4070.
April 15
Individuals
File a 2009 income tax return (Form 1040, 1040A, or 1040EZ) and pay any tax due by April 15. If you want an automatic, six-month extension of time to file the return, file Form 4868, or you can get an extension by phone or over the Internet. Then, you must file Form 1040, 1040A, or 1040 EZ by October 15.
If you are not paying your 2010 income tax through withholding (or will not pay in enough tax during the year that way), pay the first installment of your 2010 estimated tax by April 15.
Partnerships
File a 2009 calendar year return (Form 1065) by April 15. Provide each partner with a copy of Schedule K-1. If you want an automatic, five-month extension of time to file the return and provide Schedule K-1 or a substitute Schedule K-1, you must file Form 7004. Then you must file Form 1065 by September 15.
Electing large partnerships
File a 2009 calendar year return (Form 1065-B) by April 15. If you want an automatic, six-month extension, file Form 7004. Then file Form 1065 by October 15.
Corporations
Deposit the first installment of estimated income tax for 2010 by April 15.
Employers
For Social Security, Medicare, withheld income tax, and non-payroll withholding, deposit the tax for payments in March by April 15 if the monthly rule applies.
Household employers
If you paid cash wages of $1,700 or more in 2009 to a household employee, you must file Schedule H by April 15. If you are required to file a federal income tax return (Form 1040), file Schedule H with the return and report any household employment taxes. Report any federal unemployment (FUTA) tax on Schedule H if you paid total cash wages of $1,000 or more in any calendar quarter of 2008 or 2009 to household employees. Also, report any income tax you withheld for your household employees.
April 30
Employers
For Social Security, Medicare, and withheld income tax, file Form 941 for the first quarter of 2010. Deposit any undeposited tax. (If your tax liability is less than $2,500, you can pay it in full with a timely file return.) If you deposited the tax for the quarter in full and on time, you have until May 10 to file the return.
For federal unemployment tax, deposit the tax owed through March if more than $500. | 
