An Ohio state tax extension gives you up to six months past the initial filing deadline to submit your return. This means that if you are unable to file your 2010 Ohio state tax return by the filing deadline of April 18, 2011, you can qualify to have your deadline extended to October 18. However, you should only take advantage of a tax extension if there is a legitimate reason why you will be unable to submit your return on time.http://tax.ohio.gov/divisions/ohio_individual/individual/estimated_payments.stm 

In Ohio, the extension process is straightforward, since there is no state extension request that you must complete. But you cannot receive an Ohio extension unless you are already filing a federal tax extension as well.http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040_Instructions.pdf

To begin your tax extension, you need to gather all of the relevant tax paperwork that you have. This will basically be the same information you would need if you were filing your Ohio tax return now. You will need this information in order to complete step 2. The necessary documents will include the following:

1. Your Social Security number
2. Your current mailing address
3. Your date of birth
4. Your spouse's full name, date of birth and Social Security number, if you will be filing a joint tax return
5. The total earned income you received last year - This will include your wages, tips and salaries from employment as reported on your Form W-2 or Form 1099. If you are self-employed, this will be the amount of your gross earnings for the year minus any applicable business expenses.
6. The total unearned income that is subject to Ohio taxation, such as unemployment compensation, retirement distributions, rental property income, etc.
7. Your total state income tax payments made during the year - If you are an employee, this will be shown on your Form W-2 as state taxes withheld. If you work for yourself, this will be the total of any estimated tax payments you made.
8. A paper copy of Form IT-1040 "Ohio Individual Income Tax Return" and the accompanying instructions
9. A copy of your federal income tax returnhttp://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040_Instructions.pdf 
   

Since you will have to file a federal income tax extension in order to receive an Ohio extension, you may not have completed your federal return yet. But you will need your federal adjusted gross income, or AGI, in order to calculate your state taxes owed. If you need assistance with this figure, you may want to consult a tax professional.http://www.irs.gov/pub/irs-pdf/f1040.pdf

If you have access to the Internet, you can download copies of the Form IT-1040 and instructions from the Ohio Department of Taxation website. If you do not have Internet access, you can generally pick up a paper copy of the form and instructions from your local library. Even though you are not filing your return now, you will need these forms in order to assess your tax liability.http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040.pdf 

Before you begin working on the form, read the tax instructions carefully to see if there are any income adjustments you will need to make or any state tax credits that you qualify to claim. This will help you to properly estimate your taxes owed. Begin by entering the amount of your federal adjusted gross income (AGI).http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040_Instructions.pdf  

After that, add or subtract any income adjustments to arrive at your Ohio AGI. Subtract the deduction for the number of exemptions that you are eligible to claim to find your Ohio taxable income. Now, stop and consult the tax tables located in the form instructions. Find your taxable income bracket and enter the amount of tax shown. This is your tax liability.http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040.pdf   

From here, you will subtract all of the eligible state tax credits you qualify to take. Consult the instructions if you need an explanation of any of these credits. Subtract the amount of your state income tax payments. Remember, this includes your state tax withholding or estimated tax payments. What is left will be either a refund or an additional balance due.http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040.pdf 

If you calculate that you will be eligible for a refund, you can skip this step. Simply attach your IRS Form 4868 "Application for Automatic Extension of Time to File U.S. Individual Income Tax Return" to the Ohio state tax return when you file it and you will still receive the full amount of your refund. Be sure to submit the return by October 18.http://www.irs.gov/pub/irs-pdf/f4868.pdf 

On the other hand, if you have a balance due, it is important to note that, while your tax extension extends the deadline for filing, it does not extend the deadline for payment. Any additional taxes owed will still be due on April 18. If you do not remit the payment before that date, you will be charged with late filing penalties as well as compound interest until the balance is paid in full.http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT1040_Instructions.pdf  

To avoid this, send in a check or money order for the balance before that date. If you prefer, you can make your payment via a credit card or an electronic check. If you pay with a check or money order, you must use Form IT-40P "Ohio Income Tax Payment Voucher" to remit your payment. If you cannot afford to pay the entire balance before the deadline, send in what you can and contact the Department of Taxation about establishing a payment plan. This may help you to avoid late penalties.http://tax.ohio.gov/documents/forms/ohio_individual/individual/2010/PIT_IT40P.pdf

Begin working on your Ohio return immediately after you submit your payment. This will help you to avoid last minute filing as the extension deadline steadily approaches. Be sure to attach IRS Form 4868 to your state return when you file it. This will approve your state tax extension.http://www.irs.gov/pub/irs-pdf/f4868.pdf