Section 13.18 - Installment payments(a) Whenever, feasible, and except as otherwise provided by law, debts owed to the United States, together with interest, penalty and administrative costs, as required by § 13.11 , will be collected in a single payment. However, where the Administrator determines that a debtor is financially unable to pay the indebtedness in a single payment or that an alternative payment mechanism is in the best interest of the United States, the Administrator may approve repayment of the debt in installments. The debtor has the burden of establishing that it is financially unable to pay the debt in a single payment or that an alternative payment mechanism is warranted. If the Administrator agrees to accept payment by installments, the Administrator may require a debtor to execute a written agreement which specifies all the terms of the repayment arrangement and which contains a provision accelerating the debt in the event of default. The size and frequency of installment payments will bear a reasonable relation to the size of the debt and the debtor's ability to pay. The installment payments will be sufficient in size and frequency to liquidate the debt in not more than 3 years, unless the Administrator determines that a longer period is required. Installment payments of less than $50 per month generally will not be accepted, but may be accepted where the debtor's financial or other circumstances justify. If the debt is unsecured, the Administrator may require the debtor to execute a confess-judgment note with a tax carry-forward and a tax carry-back provision. Where the Administrator secures a confess-judgment note, the Administrator will provide the debtor a written explanation of the consequences of the debtor's signing the note.(b) If a debtor owes more than one debt and designates how a voluntary installment payment is to be applied among the debts, that designation will be approved if the Administrator determines that the designation is in the best interest of the United States. If the debtor does not designate how the payment is to be applied, the Administrator will apply the payment to the various debts in accordance with the best interest of the United States, paying special attention to applicable statutes of limitations.