If you can't pay your taxes, the IRS will set up a payment plan and mail out the paperwork for you to sign. You even get to choose the monthly payment day as long as it's between the 1st and the 28th. Or download Form 9465 from the IRS website and mail it in. You will receive a response within 30 days. You do have the option of filing an extension using Form 4868. Regardless of which one you choose, don't blow it off! The penalty for not filing is 5% per month up to a max of 25% of balance due. Did you know you could file an extension and pay taxes at the same time? There are two IRS-approved credit card services. One is Link2Gov offering extension payments and the other is called Official Payments. There is a 2.49% convenience fee for using either service.