144.140.  Seller may retain two percent of tax — certified service provider, monetary allowance from taxes in lieu of two percent retention. — 1.  From every remittance to the director of revenue made on or before the date when the same becomes due, the person required to remit the same shall be entitled to deduct and retain an amount equal to two percent thereof.

  2.  The director shall provide a monetary allowance from the taxes collected to a certified service provider under the terms of the certified service contract signed with the provider, provided that such allowance shall be funded entirely from moneys collected by the certified service provider.

  3.  Any certified service provider receiving an allowance under subsection 2 of this section shall not be entitled to simultaneously deduct the allowance provided for under subsection 1 of this section.

  4.  For the purposes of this section, "certified service provider" shall mean an agent certified by the department of revenue to perform all the seller's sales and use tax functions, other than the seller's obligation to remit tax on its own purchases.

  5.  The provisions of this section relating to the allowance for timely remittance of sales tax payment shall also be applicable to the timely remittance of use tax payment under sections 144.600 to 144.746.