If you have taxes that you will not be able to pay in a future taxation year, you can add this new balance to your existing agreement. This is not a second agreement. You will be charged interest and penalties on the total amount of your late balance until it is fully resolved. If you already have an installment contract and you also owe taxes for the current year, you must act quickly to request a change to your existing installment contract. Once a new tax balance has been assessed by the IRS, you will be considered in arrears with the current agreement. You can request a change to the instalment payment contract in: However, you may need to prove your financial situation. Complete any of these steps before the due date of the applicable tax year to avoid collection actions that do not meet your existing instalment payment agreement. Start and submit your 2019 tax return first. . .