(a) Requirement—(1) In general: after 1983 and before April 1, 1991. In the case of a calendar month which begins after December 31, 1983, and before April 1, 1991, if, at a time prescribed under § 31.6302(c)-1(a)(1) (i) or (v) for the deposit of undeposited taxes, the aggregate amount of undeposited employee tax withheld after December 31, 1983, and before April 1, 1991, under section 3202 and employer tax imposed after December 31, 1983, and before April 1, 1991, under section 3221(a) and (b) equals an amount required to be deposited under § 31.6302(c)-1(a)(1) (i) or (v) the employer shall deposit the undeposited railroad retirement taxes described in sections 3202 and 3221 at such time in the manner prescribed in § 31.6302(c)-1(a)(1) (i) or (v) (except that undeposited railroad retirement taxes described in section 3221 (c) shall in no case be required to be deposited earlier than the first day on which a deposit is otherwise required by § 31.6302(c)-1(a)(1)(i) to be made after the 15th day of the month following the month in which the section 3221 (c) tax arises).

(2) In general: After March 31, 1991 and before January 1, 1993. In the case of a calendar month which begins after March 31, 1991, if, at a time prescribed under § 31.6302(c)-1(a)(1)(ii) or (v) for the deposit of accumulated taxes, the aggregate amount of accumulated employee tax withheld after March 31, 1991, under section 3202 and employer tax imposed after March 31, 1991, under section 3221(a) and (b) equals an amount required to be deposited under § 31.6302(c)-1(a)(1)(ii) or (v), the employer shall deposit the accumulated railroad retirement taxes described in sections 3202 and 3221 at the time and in the manner prescribed in § 31.6302(c)-1(a)(1)(ii) or (v) (except that accumulated railroad retirement taxes described in section 3221(c) shall in no case be required to be deposited earlier than the first day on which a deposit is otherwise required by § 31.6302(c)-1(a)(1)(ii) to be made after the 15th day of the month following the month in which the section 3221(c) tax arises). Notwithstanding the preceding sentence, and notwithstanding § 31.6302(c)-1(a)(1)(v), if, for the calendar year prior to the calendar year preceding the current calendar year, the aggregate amount of taxes imposed under sections 3202 and 3221 with respect to an employer equalled or exceeded $1 million, such employer shall deposit the aggregate amount of railroad retirement taxes required to be deposited for the current calendar year in accordance with Revenue Procedure 83-90, 1983-2 C.B. 615 (relating to transfers by wire to the Treasury).

(3) Special requirement. If an employer files a return on Form CT-1 for a return period beginning before January 1, 1984, and the taxes shown thereon exceed by more than $100 the total amount deposited by him pursuant to paragraph (a)(1) of this section for such return period the employer shall, on or before the last day of the second calendar month following the period for which the return is filed, deposit with a Federal Reserve bank or authorized financial institution an amount equal to the amount by which the taxes shown on the return exceed the total deposits (if any) made pursuant to paragraph (a)(1) of this section for such return period.

(b) Depositary forms—(1) In general. A deposit required to be made by this section shall be made separately from a deposit required by any other section. An employer may make one, or more than one remittance of the amount required to be deposited. An amount of tax which is not required to be deposited may nevertheless be deposited if the employer so desires. If the aggregate amount of the taxes deposited is in excess of the taxes shown on the return, a credit or refund may be obtained; and in the event the excess is applied as a credit against such taxes for a subsequent return period, the employer shall reduce the amount of one or more of the deposits otherwise required for such subsequent return period by the amount of such credit.

(2) Deposits. Each remittance of amounts required to be deposited shall be accompanied by a Federal Tax Deposit form which shall be prepared in accordance with the instructions applicable thereto. Except as provided in paragraph (a)(1) or (a)(2) of this section, the remittance, together with the form, shall be forwarded to a financial institution authorized as a depositary for Federal taxes in accordance with 31 CFR part 214 or, at the election of the employer, to a Federal Reserve bank. For procedures governing the deposit of Federal taxes at a Federal Reserve bank, see 31 CFR part 214.7. The timeliness of the deposit will be determined by the date stamped on the Federal Tax Deposit form by the Federal Reserve bank or the authorized financial institution or, if section 7502(e) applies, by the date the deposit is treated as received under section 7502(e). Each employer making deposits under this section shall report on the return, for the period with respect to which such deposits are made, information regarding such deposits according to the instructions that apply to such return and pay at that time (or deposit by the due date of such return) the balance, if any, of the taxes due for such period.

(3) Time deemed paid. In general, amounts deposited under subparagraph (2) of this paragraph shall be considered as paid on the last day prescribed for filing the return in respect of such tax (determined without regard to any extension of time for filing such return), or at the time deposited, whichever is later. For purposes of section 6511 and the regulations thereunder, relating to period of limitation on credit or refund, if an amount is so deposited prior to April 15th of a calendar year immediately succeeding the calendar year in which occurs the period for which such amount was so deposited, such amount shall be considered as paid on such April 15th.

(c) Procurement of prescribed form. Copies of the Federal Tax Deposit form will so far as possible be furnished employers. An employer will not be excused from making a deposit, however, by the fact that no form has been furnished to it. An employer not supplied with the form should make application therefor in ample time to make the required deposits within the time prescribed. The employer may secure the form or additional forms by applying therefor and supplying its name, identification number, address, and the taxable period to which the deposits will relate. Copies of the Federal Tax Deposit form may be secured by application therefor.