26 CFR § 1.6302-4 - Voluntary payments by electronic funds transfer.
(a) Electronic funds transfer. Any person may voluntarily remit by electronic funds transfer any payment of tax imposed by subtitle A of the Internal Revenue Code, including any payment of estimated tax. Such payment must be made in the manner set forth in published guidance, publications, forms and instructions.
(b) Effective/applicability date. This section applies to deposits and payments made after December 31, 2010.