An approved extension in the state of New York will allow you to have six additional months to file your return. This means that the filing deadline for your 2010 New York state tax return will be October 17, 2011, instead of April 18, 2011. If you were to simply file late without an extension, you would be assessed a late filing penalty, along with compound interest on any balance due owed.http://www.tax.ny.gov/pdf/2010/inc/it150_201i_2010.pdf 

It should be noted, however, that an approved extension does not extend the deadline for any payment due. If you estimate that you will owe additional taxes, you need to make arrangements to pay these before April 18, 2011 in order to avoid penalties.http://www.tax.ny.gov/pdf/2010/fillin/inc/it370_2010_fill_in.pdf

To begin your extension process, you need to gather all of your important tax documents. Since you will need to assess your taxes owed, you will need everything that you will use to prepare your state tax return. This includes the following:

1. Your total earned income for the year - For employees, this will be the total earnings as reported on your Form W-2 or Form 1099. For self-employed individuals, this will be the total of gross earnings minus any applicable business expenses.
2. Your total unearned income for the year that is subject to New York state taxation - Among other things, this includes unemployment compensation, retirement payments, and lottery winnings.
3. The total amount of state income taxes that you have already paid in - If you are employed, this will appear on your Form W-2 as state taxes withheld. If you are self-employed, this will be the amount of any estimated tax payments you made.
4. A copy of your federal income tax return, if you are filing onehttp://www.tax.ny.gov/pdf/2010/inc/it150_201i_2010.pdf 
   

Since you will need to figure your state tax liability in order to assess any taxes you will owe, you will need a paper copy of Form IT-201 "New York Resident Individual Income Tax Return." If you have access to the Internet, you can download this form and the accompanying instructions online. If you do not have Internet access, you can pick up a paper copy of the form and instructions from your local library.http://www.tax.ny.gov/pdf/2010/fillin/inc/it201_2010_fill_in.pdf

If you will need to complete the extension form, you will also need all of the following information:

1. Your Social Security number
2. Your current mailing address
3. Your spouse's name and Social Security number, if you are filing a joint tax return/extensionhttp://www.tax.ny.gov/pdf/2010/fillin/inc/it370_2010_fill_in.pdf 

Now you are ready to begin assessing your tax liability. Your tax liability is the total amount of tax that is owed on the part of your income that is taxable under New York state tax laws. Once you figure this amount, you can prepare to make a payment if necessary.http://www.tax.ny.gov/pdf/2010/inc/it150_201i_2010.pdf

Before you begin working through the state tax return, stop and read the form instructions. This section will explain exactly what sources of income are subject to tax as well as state credits that you may qualify to claim. Start completing the New York state tax return by entering the requested figures from your IRS Form 1040 on lines 1-18. If you are not filing a federal income tax return, you may want to consult a tax professional to help you arrive at these figures.http://www.tax.ny.gov/pdf/2010/inc/it150_201i_2010.pdf 

Once you get to line 19, stop and check the instructions for any income adjustments you need to make. Then continue working through the form until you reach line 33, New York adjusted gross income. At this point, you will subtract your deductions and dependent exemptions to calculate your taxable income in the state New York.http://www.tax.ny.gov/pdf/2010/fillin/inc/it201_2010_fill_in.pdf 

Look through the tax tables located in the form instructions to assess the amount of tax that is imposed on your income bracket. This will be your actual tax liability. After you subtract any state credits that you are eligible to claim, you will deduct the amount of your state income taxes paid through withholding from earnings or estimated tax payments. This will leave you with either a refund due to overpayment or a balance due from underpayment.http://www.tax.ny.gov/pdf/2010/inc/it150_201i_2010.pdf 

Once you have assessed the amount of taxes you owe, you can file for your extension. If you do not owe any additional taxes and you are already filing a federal tax extension, you can simply submit a copy of your IRS Form 4868 to the New York Department of Taxation and Finance to receive your state extension.http://www.irs.gov/pub/irs-pdf/f4868.pdf 

But, if you are simply filing a New York state extension, you will need to fill out Form IT-370 "Application for Automatic Six-Month Extension of Time to File for Individuals." This form can also be downloaded from the Department of Taxation and Finance website or picked up from the library. If you prefer to file your request electronically, you can do so directly through the Department website.http://www.tax.ny.gov/pdf/2010/fillin/inc/it370_2010_fill_in.pdf 

Begin the extension request by entering your Social Security number and full name, as well as your spouse's, if applicable. Complete the address portion and then select the taxes to which you are subject. On the line for total payment, you will enter the amount of tax that you are paying along with the form. If you are due a refund, enter zero on this line.http://www.tax.ny.gov/pdf/2010/fillin/inc/it370_2010_fill_in.pdf 

Then, make a copy of the form for your records and enclose it with a check or money order for your tax balance in an envelope and send it to the address given on the form. Be sure to submit it before April 18. If you cannot pay your entire tax balance at once, send in what you can and contact the Department of Taxation and Finance about establishing a payment plan.http://www.tax.ny.gov/pdf/2010/fillin/inc/it370_2010_fill_in.pdf

Now that you have completed your extension filing, you need to start working on your state tax return as soon as possible. If you need assistance, you may want to learn about how to prepare New York taxes. If you're still in need of help, it is advisable to consult a tax professional.