Use Form 9465 to request a monthly installment plan if you cannot pay the full amount you owe shown on your tax return (or on a notice we sent you). Applying online has the lowest application fees.Use Form 9465 to request a monthly installment agreement (payment plan) if you can't pay the full amount you owe shown on your tax return. You defaulted on your IRS payment plan? You still have options to get back in good standing with the IRS and avoid collection activity. To ask for an installment agreement, complete this form. Attach it to the front of your return when you file. Electronically file and pay your current or prior sales and use tax return (E-500) using our online filing and payment system. Under the agreement, you'll make monthly payments toward your unpaid tax balance. The SCDOR is granting relief to South Carolina taxpayers in the wake of Hurricane Helene.