(a) General. -- Every employer or payor of a pension or annuity required to deduct and withhold tax under this act shall, for each calendar month, on or before the 15th day of the month following the close of such calendar month, file a withholding return as prescribed by the director and pay over to the director or to a depository designated by the director the taxes so required to be deducted and withheld. Any return due with respect to the last quarter of a calendar year shall be filed and the amount of the withholding shall be paid on or before January 31 next following. The director may, if the director believes such action necessary for the protection of the revenues, require any employer or payor of a pension or annuity to make such return and pay to the director the tax deducted and withheld at any time, or from time to time. Where the amount of wages paid by an employer is not sufficient under this act to require the withholding of tax from the wages of any of that employer's employees, the director may, by regulation, permit such employer to file an annual return on or before February 28 of the following calendar year. The director may, by regulation, require the filing and payment of withholding returns and taxes on a semimonthly or more frequent basis or require the filing of returns on a quarterly basis, with payments of the taxes withheld on a monthly or more frequent basis, if the director deems such action in the best interest of the State.