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). The IRS Online Payment Agreement system lets you apply and receive approval for a payment plan to pay off your balance over time.The IRS offers payment alternatives if you can't pay in full. You can ask for a short-term payment plan for up to 120 days. 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 can request a Payment Plan: Online using your GTC account. Most of our letters provide specific instructions of what you need to do. Once completed, use these instructions to submit your application. ​. ⇒ Completed Form 9465 (Installment Agreement Request) or applied for Installment Agreement online. ⇒ Filed all past tax returns.