SECTION 4. PROCEDURES FOR

MAKING DEPOSITS UNDER SECTION 6603; TREATMENT OF OTHER REMITTANCES

.01 In General . (1) A taxpayer may make a deposit under section 6603 by remitting to the Internal Revenue Service Center at which the taxpayer is required to file its return, or to the appropriate office at which the taxpayer’s return is under examination, a check or a money order accompanied by a written statement designating the remittance as a deposit. The written statement also must include:

(a) The type(s) of tax; (b) The tax year(s); and (c) The statement described in section 7.02 identifying the amount of and basis for the disputable tax.

(2) Except as provided in sections 4.04(1) and 4.05(3), a remittance that is not designated as a deposit (an “undesignated remittance”) will be treated as a payment and applied by the Service against any outstanding liability for taxes, penalties or interest. Undesignated remittances treated as payments will be applied to the earliest taxable year for which there is a liability, and will be applied first to tax, then penalties and finally to interest. An undesignated remittance treated as a payment of tax will be posted to the taxpayer’s account as a payment upon receipt, or as soon as possible thereafter, and may be assessed, provided that assessment will not imperil a criminal investigation or prosecution. The amount of an undesig

2005–13 I.R.B. 799 March 28, 2005