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). 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.An installment agreement breaks tax debt into manageable monthly payments. The IRS Online Payment Agreement system lets you apply and receive approval for a payment plan to pay off your balance over time.