WASHINGTON -- Do you figure to owe the Internal Revenue Service a big tax bill this year but wonder where the money will come from?

There is a wide array of options for those who can't pay all at once. Taxpayers who are unable to file their tax return by midnight April 15 also can ask for an automatic four-month extension. Any taxes owed, however, must be paid on time to avoid interest and late penalties.

Taxpayers can contact the IRS to request on automatic extension by calling (888) 796-1074 beginning March 1, or they can use IRS form 4868. For an additional two months -- the IRS doesn't automatically grant these -- use form 2688.

If you don't see a way to pay your taxes even with an extension, the IRS may allow you to pay your balance over time through an installment agreement or possibly even settle for less than the full amount owed through its offer in compromise program.

To apply for an installment payment plan, attach a Form 9465, Installment Agreement Request, to the front of your tax return. The IRS has streamlined the approval process if the amount owed is not more than $25,000 and can be paid off within a five-year period. Be sure to show the amount of your proposed monthly payment and the date you wish to make your payment each month.

The IRS charges a $43 fee for setting up an installment agreement. You will also be required to pay interest plus a late payment penalty on the unpaid balance. This penalty, usually 0.5 percent of the balance due per month, drops to a 0.25 percent rate when the IRS approves the installment agreement if your return was filed on time and you did not receive a levy notice from the IRS.

If you find that you cannot possibly come up with the money to pay your taxes, even through an installment plan, you may apply for an offer in compromise to settle your tax debt for less than the full amount owed. Send Form 656, Offer in Compromise, and Form 433-A, Collection Information Statement, to the IRS to determine your eligibility. There is a $150 application fee.

Now, about that tax bill. Here are some ways to pay:

You can charge your taxes on your American Express, MasterCard, Visa or Discover Card. To pay by credit card, contact either Official Payments Corp. or Link2Gov Corp. Read more about these options on the IRS site.
One thing to consider, tax experts said, is whether it is worth using a credit card that charges a high interest rate. You may want to instead consider applying for an IRS installment agreement.
Taxpayers who file returns electronically can have their taxes due debited by the IRS from a checking or savings account. Taxpayers can specify the date for the debit, meaning they can file their return early and then wait as late as April 15 to pay the bill.