40-5-416. Determination of amount of income to be withheld. (1) (a) Subject to the limitations provided in subsection (2), the amount of funds to be withheld each month from the obligor's income must be the amount of money necessary to pay current installments of support as they become due and payable.
(b) If income is being withheld to satisfy an arrearage, the amount of funds to be withheld must include the greater of:
(i) the amount of money that, when deducted in equal amounts each month, will pay all outstanding support arrearages and interest, if any, within 2 years; or
(ii) 25% of the obligor's income.
(c) If income is being withheld under this part, the department may allow a fee not to exceed $5 each month, which may be withheld by the payor as compensation for the administrative costs of each withholding.
(d) If a support order subject to income withholding is expressed in terms of a monthly obligation, the order may be annualized and withheld on a weekly or biweekly basis, corresponding to the obligor's regular pay period. If withholding is annualized, when deducted in equal amounts, the amount withheld each pay period must be sufficient to pay all installments due in a 12-month period under the order to withhold.
(2) The maximum amounts withheld from the obligor's wages or salaries, including fees, may not exceed the maximum amount permitted under section 303(b) of the federal Consumer Credit Protection Act, 15 U.S.C. 1673(b), as amended.
(3) At any time, if the obligor can show that substantial hardship will result if the maximum permissible withholding is implemented or continued, the department for cause shown may in its discretion determine a lesser amount to be withheld each month in satisfaction of support arrearages.