In the case of tips which constitute wages, subsection (a) shall be applicable only to such tips as are included in a written statement furnished to the employer pursuant to section
6053
(a), and only to the extent that the tax can be deducted and withheld by the employer, at or after the time such statement is so furnished and before the close of the calendar year in which such statement is furnished, from such wages of the employee (excluding tips, but including funds turned over by the employee to the employer for the purpose of such deduction and withholding) as are under the control of the employer; and an employer who is furnished by an employee a written statement of tips (received in a calendar month) pursuant to section
6053
(a) to which paragraph (16)(B) of section
3401
(a) is applicable may deduct and withhold the tax with respect to such tips from any wages of the employee (excluding tips) under his control, even though at the time such statement is furnished the total amount of the tips included in statements furnished to the employer as having been received by the employee in such calendar month in the course of his employment by such employer is less than $20. Such tax shall not at any time be deducted and withheld in an amount which exceeds the aggregate of such wages and funds (including funds turned over under section
3102
(c)(2) or section
3202
(c)(2)) minus any tax required by section
3102
(a) or section
3202
(a) to be collected from such wages and funds.