April 10  - 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 an income tax return for 2007 (Form 1040, 1040A, or 1040EZ) and pay any tax due. If you want an automatic 6-month extension of time to file the return, file Form 4868, Application for Automatic Extension of Time To File U.S. Individual Income Tax Return, or you can get an extension by phone if you pay part or all of your estimate of income tax due with a credit card. Then file Form 1040, 1040A, or 1040EZ by October 15. 

Household employers. If you paid cash wages of $1,500 or more in 2007 to a household employee, file Schedule H (Form 1040) with your income tax return and report any 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 2006 or 2007 to household employees. Also report any income tax you withheld for your household employees. 

Individuals. If you are not paying your 2008 income tax through withholding (or will not pay in enough tax during the year that way), pay the first installment of your 2008 estimated tax. Use Form 1040-ES. 

Partnerships. File a 2007 calendar year return (Form 1065). Provide each partner with a copy of Schedule K-1 (Form 1065), Partner's Share of Income, Credits, Deductions, etc., or a substitute Schedule K-1. If you want an automatic 6-month extension of time to file the return and provide Schedule K-1 or a substitute Schedule K-1, file Form 7004. Then file Form 1065 by October 15. 

Electing large partnerships. File a 2007 calendar year return (Form 1065-B). If you want an automatic 6-month extension of time to file the return, file Form 7004. Then file Form 1065-B by October 15. See March 15 for the due date for furnishing the Schedules K-1 to the partners. 

Corporations. Deposit the first installment of estimated income tax for 2008. A worksheet, Form 1120-W, is available to help you estimate your tax for the year. 

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

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

April 30 - Employers Social Security, Medicare, and withheld income tax. File form 941 for the first 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 May 10 to file the return. 

Employers Federal Unemployment Tax. Deposit the tax owed through March if more than $500.