Fairness in IRS Debt Payment Act of 1999

[AI summary unavailable — showing source text] Fairness in IRS Debt Payment Act of 1999 - Amends the Internal Revenue Code to compute interest on the tax portion of underpayments annually (currently daily). Allocates payments for taxable period underpayments equally among such periods or as directed by the taxpayer. Prohibits the Secretary of the Treasury from modifying certain voluntary installment agreements other than for reasons of nonpayment. Requires abatement of aggregate tax interest and penalties in excess of the amount of such tax. Requires the Secretary to: (1) prescribe penalty abatement guidelines; and (2) provide a requesting taxpayer with a written explanation for nonabatement of a penalty.…