April
We 15 Individuals: File Form 1040, 1040A, or 1040EZ. For automatic 6-month extension file Form 4868 and deposit estimated tax. Pay the first installment of 2015 estimated tax.
We 15 Partnerships: File Form 1065 and furnish a copy of Sch. K-1 to each partner.
We 15 Electing Large Partnerships: File Form 1065-B calendar year return.
We 15 Household Employers: File Sch. H with Form 1040 if you paid $1,900 or more to a household employee.
We 15 Corporations: Deposit the first installment of your 2015 estimated tax.
Th 30 Employers: File Form 941 for the first quarter.
Th 30 Deposit FUTA tax owed through Mar if more than $500.
May
Mo 11 File Form 941 for the first quarter if you timely deposited all required payments.
June
Mo 15 Individuals living outside the U.S.: File Form 1040.
Mo 15 Individuals: Pay the second installment of 2015 estimated tax.
Mo 15 Corporations: Deposit the second installment of your 2015 estimated tax