California state tax laws require that tax returns for the year 2010 be submitted by April 18, 2011.  If you are unable to file your forms by that date, you should take steps to receive a state extension. If you have a balance due on your return, any unpaid balance will be charged with a late filing penalty as well as compound interest on the taxes outstanding. You can avoid these penalty charges by receiving an extension.http://www.ftb.ca.gov/individuals/important_duedates.shtml 

In California, there is no written extension request you will have to complete. You will automatically receive a six-month extension if you are unable to file on time, pushing your filing deadline back to October 18, 2011. You will still have to make payment of any taxes owed by April 18 to avoid the interest charges.http://www.ftb.ca.gov/individuals/faq/ivr/201.shtml 

Your first step to getting a California state extension is to collect all of the information needed to prepare your request. These will be the same documents used to complete your federal return, so keep them in one place for use later. You will need the following:

1. Your earned income received during the year––If you are employed, use the total of your taxable wages as shown on Form W-2 or Form 1099. If you are self-employed, total your gross earnings and deduct any applicable business expenses to figure your net income.
2. Your unearned income received that is also subject to state tax––This includes lottery winnings, pension payments and rental property income. Unemployment compensation is not taxable in California. See the tax form instruction booklet for a complete list of taxable income sources.
3. The total of state income taxes paid ––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 made.
4. A copy of your completed federal income tax return, if you will be filing one

Your California state tax liability will be based on your federal adjusted gross income, so you should complete your federal forms before you begin your state return. If you will not be filing a federal return at this time, you may wish to consult a tax professional for help calculating this figure.http://www.ftb.ca.gov/forms/2010/10_540bk.pdf  

If you will have 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.ftb.ca.gov/forms/2010/10_540bk.pdf 

To assess your state tax liability, retrieve a paper copy of Form 540 "California Resident Income Tax Return" and the tax form instruction booklet. If you have access to the Internet, you can download these from the California Franchise Tax Board website. If you do not have Internet access, you can generally pick up hard copies of these at your local library.http://www.ftb.ca.gov/forms/2010/10_540bk.pdf 

Read the tax form instruction booklet before you begin. This will help you understand any income adjustments you have to make, as well as any state tax credits you can claim. Start working through the tax form by entering your state taxable wages as shown on Form W-2 on line 12. Carry the total of your federal adjusted gross income from IRS Form 1040 over to line 13 of the California form.http://www.ftb.ca.gov/forms/2010/10_540bk.pdf 

On lines 14 through 16, make any additions and subtractions to income as needed to calculate your California adjusted gross income on line 17. Subtract your standard or itemized deductions to arrive at your net taxable income on line 19. Consult the tax table to assess the amount of taxes owed on your taxable income. Enter this on line 31 as your tax.http://www.ftb.ca.gov/forms/2010/10_540bk.pdf 

Deduct any state tax credits you can claim as well as your state income taxes already paid through withholding or estimated tax payments. Your final result will be either an additional balance due on line 110 or a refund on line 115.http://www.ftb.ca.gov/forms/2010/10_540bk.pdf

If you will be entitled to receive a refund or if you have a zero balance, you can stop at this point. Simply file your return when you are able and you should still be able to receive any refund you are due. But if you have a balance due, you will need to remit your payment before the filing deadline to avoid being charged a late payment penalty and additional compound interest.http://www.ftb.ca.gov/forms/2010/10_540a_540ins.pdf 

To submit your payment, you can pay online through the California Franchise Tax Board website or you can pay using a check or money order through the mail. If you choose to pay by mail, you need to complete Form FTB-3519 "Payment for Automatic Extension for Individuals." This form is also available for download on the tax board website.http://www.ftb.ca.gov/forms/2010/10_3519.pdf 

Enter your full name and Social Security number as well as your spouse's, if applicable, on the form. Write in your current mailing address and the amount of the payment you are making. Send the completed voucher, along with the check or money order, to the address listed on the form. Be sure to submit both by April 18, 2011.http://www.ftb.ca.gov/forms/2010/10_3519.pdf

If you are unable to pay the entire balance at once, send in what you can afford and then contact the Franchise Tax Board about establishing a payment plan. Once you remit payment, begin working on your California state return as soon as possible.