All 2010 individual state income tax returns in Iowa are due on May 2, 2011. But if you are not able to file your return by that date, you should arrange for an extension. If you choose to file your return late without any notification, you will be assessed a late filing penalty as well as compound interest on any taxes you owe. On the other hand, if you request an extension and remit your payment before the deadline, you will avoid these excess charges.c 

An approved extension will give you an extra six months to file your return. This means your new filing deadline will be October 31. It is important to note, however, that the extension does not apply to any outstanding tax balance you have. If you will owe additional taxes on your return, you will still have to remit these in full before May 2.c 

To begin preparing your Iowa extension, you need to get all of your necessary tax documents together. You will basically need the same information you will use to prepare your Iowa state return. This includes the following:

1. The total earned income you received during the year––If you are employed, this will be the amount shown on your Form W-2 or Form 1099 as total taxable wages. If you are self-employed, use the amount of your gross earnings minus any applicable business expenses.
2. The total unearned income you received that is subject to Iowa state taxation––Among other things, this includes unemployment compensation, lottery winnings, bank interest and dividends, etc.
3. Your state income taxes already paid during the year––Employees generally have this done through state tax withholding from wages. This will be reported to you on Form W-2 as state taxes withheld. Self-employed taxpayers will use the amount of any estimated state tax payments made.
4. A copy of your federal income tax return, if you will be filing one 

If you will be filing a federal return, complete those forms before requesting your Iowa extension. This will help you to plan for the additional tax owed, if any. If you need to get a federal tax extension as well, you'll need to complete a separate form for your federal taxes. Whenever you file your federal return, be sure to use the same filing status and exemptions on both your federal and Iowa tax forms.c

To complete the written payment voucher, if necessary, you will also need the following:

1. Your Social Security number
2. Your complete mailing address
3. The full name and Social Security number of your spouse, if you will be filing a joint tax returnc 
   

Your next step to getting an Iowa extension is to calculate the amount of state taxes you will owe, if any. To do this properly, you will need a paper copy of Form IA-1040 "Iowa Individual Income Tax Long Form" and the accompanying instructions. You can download both of these from the Iowa Department of Revenue website or you can obtain these at your local public library.c 

Read the tax forms carefully before beginning the tax forms. The instructions will explain any adjustments to income you will need to make as well as state tax credits you may qualify to claim. Begin the form by entering your income on lines 1 through 14, separated by type. On line 15, you will add these to reach your gross income.c   

Make any applicable income adjustments on lines 16 through 25. Subtract these from line 15 to calculate your net income. On lines 26 through 34, you will make income adjustments to account for income that is taxable by the federal government but not the state of Iowa and vice versa. After this, you will deduct your standard or itemized deductions and exemptions to calculate your Iowa taxable income.c 

Next, consult the tax tables to assess exactly how much tax is due on your taxable income bracket. Enter this amount on line 43 and then include any additional taxes to figure your total tax due on line 46. Deduct all state tax credits that you qualify to claim and then subtract your state income taxes already paid through withholding or estimated payments. The amount that remains will be either an overpayment (refund) or an underpayment (balance due).c 

If you calculated that you are due a refund, you can skip this step. Simply file your return when you are able to complete it and you should still receive your full refund amount. If you have a zero balance due, you can also skip this step. But if you have an additional balance due, you will need to remit your balance due before the filing deadline in order to receive your extension.c 

For fastest processing, pay your balance online through the Iowa Department of Revenue website. You can arrange to have your balance directly debited from your bank account for no charge. If you prefer to remit your payment by mail, you will need to complete Form 41-137 "Iowa Individual Income Tax Payment Voucher". This form is also available for download on the state revenue website.c 

Complete the payment voucher by entering your name and Social Security number, as well as your spouse's if necessary. Fill in your current mailing address and the total of your tax payment. Send the voucher along with a check or money order to the address listed on the form. Be sure to submit it by May 2.c 

If you will not be able to pay your entire balance at once, send in what you can and then contact the Iowa Department of Revenue about establishing a payment plan.c To avoid last minute rushing, try to start on your state tax return as soon as possible after remitting your payment.