The filing deadline for submitting an Alabama state tax return is April 18, 2011, so any tax form filed after that date will generally be subject to a late filing penalty and compound interest on the amount of tax owed. However, if you take the steps to receive an approved tax extension, you can avoid both of these charges. You will also receive an extra six months to submit your return, giving you a new filing deadline of October 15.http://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf 

It is important to note, however, that an approved tax extension does not extend the due date of any additional state tax that is due. Therefore, if you will owe additional taxes with your return, you will still have to remit your balance in full before April 18 to avoid interest charges.http://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf 

To get started on your Alabama tax extension, your first step is to gather all the necessary information for the process. These will be the same documents needed to complete the tax return, so you should to keep them together for easy reference later. You will need the following:

1. Your total earned income for the year––If you are employed, this amount will be reported to you on Form W-2 or Form 1099 as state taxable wages. If you are self-employed, add up your gross earnings received and deduct any applicable business expenses.
2. Your total unearned income that is also subject to state tax––Among other things, this includes bank interest, dividends and retirement distributions. Alabama is one of the few states that does not tax unemployment compensation. See the tax form instructions for a complete list of taxable income sources.
3. The amount of state income taxes you have already paid during the year - Employees will see this on Form W-2 as state taxes withheld. Self-employed taxpayers will use the total of any estimated state tax payments they have made.
4. A copy of your completed federal income tax return, if you are filing one

Unlike many other states, Alabama does not base its state tax calculations on the amount of your federal adjusted gross income. But if you are filing a federal return, keep it nearby. This will help you to report exemptions, filing status and income information consistently on both forms.http://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf     

To remit a payment, you will also need the following:

1. Your Social Security number
2. Your current mailing address
3. The full name and Social Security number of your spouse, if you will be filing a joint tax returnhttp://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf 

The next step is to assess the amount of your state tax liability and determine whether you will owe any additional taxes with your return. To do this, you will need to get a paper copy of Form 40 "Alabama Individual Income Tax Return" and the tax form instruction booklet. If you have Internet access, you can download these from the Alabama Department of Revenue website. If you do not have access to the Internet, you can usually obtain a hard copy of these forms at your local library during tax season.http://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf 

Before working through the form, however, be sure to stop and read the tax instruction booklet carefully. Pay particular attention to the sections regarding taxable income and tax credits. If any part of the form seems confusing, consult the instruction booklet before completing it.http://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf 

Start the form by entering your earned income on line 5 and your interest income on line 6. If you have income from other sources, turn to Part 1 on page 2 of the form to list them. Carry the total of these to line 7 on page 1 and then add up all your income on line 8. Now, turn back to page 2 and complete Part 2 to make any necessary income adjustments to account for income that is not taxable in Alabama. Carry this total to line 9 on page 1 and then subtract this from line 8 to arrive at your state adjusted gross income on line 10.http://www.revenue.alabama.gov/incometax/2010_forms/10f40blk.pdf

On lines 11 through 15, you will subtract your standard or itemized deductions and your personal exemption allowances. These will generally have to be same ones you claimed on your federal return. Once you total your deductions on line 15, subtract them from your adjusted gross income to calculate your taxable income on line 16.http://www.revenue.alabama.gov/incometax/2010_forms/10f40blk.pdf 

Consult the tax table to locate the amount of state tax you owe on your income. Enter this as your tax on line 17. Then, deduct any eligible state tax credits you can claim and your state income taxes already paid in through withholding or estimated payments. The result will be either a balance due on line 28 or a refund on line 33.http://www.revenue.alabama.gov/incometax/2010_forms/10f40blk.pdf

If you have additional tax due, you will need to complete a written extension request and submit along with your tax payment before April 18. The form you will need to send in is Form 40V "Alabama Income Tax Payment Voucher". This can also be downloaded from the Alabama State Tax Commission website or picked up at the public library. Complete the form by entering your full name and Social Security number, as well as your spouse's if applicable. Fill in your complete mailing address and the amount of the payment you are making.http://www.revenue.alabama.gov/incometax/2010_forms/f40v.pdf 

In order to avoid late payment penalties and compound interest, you will want to remit the entire outstanding balance before April 18. Write out a check or money order for the total and send it in with the extension request to the address stated on the form. If you are unable to pay the entire balance at once, send in what you can and then contact the Alabama State Tax Commission about establishing a payment plan.http://www.revenue.alabama.gov/incometax/2010_forms/f40v.pdf 

If your extension request is approved, you will have until October 17 to submit your completed state return.http://www.revenue.alabama.gov/incometax/2010_forms/10f40bk.pdf However, it is still a good idea to begin preparing your return immediately after remitting your payment.