Owe money to the IRS, consider these tax payment options.

E-options?
These options offer taxpayers the easiest and fastest way to make a full or partial payments. You can either pay by phone, online or using your credit card.
A short-term extension gives a taxpayer up to 120 days to pay without processing fee, but the late payment penalty and interest still apply.
A monthly payment plan or installment agreement gives the taxpayer more time to pay. Under this method the interest still apply but the late payment penalty is cut in half to 0.25 percent for any month an installment agreement is in effect.
Penalties for filing or paying taxes late.
Filing late. You must pay a failure- to-file penalty. The penalty is usually 5% per month for each month that a return is late, not to exceed 25%. The penalty is based on the tax not paid by the due date.
Paying tax late. The penalty is 0.5% of your unpaid taxes for each month that the tax is due. This could increase to 1 percent per month after a notice of deficiency is received.
Combined Penalties. The penalty for filing late is reduced by the penalty for paying late for that month, unless the minimum penalty for filing late is charged.
Accuracy related penalties. If due to understatement could reach 20 percent. (Source: IRS)