Each employer shall make contributions for each year after nineteen hundred and ninety-one at the applicable rate or rates as set forth in this section on so much of its payroll as is subject to this chapter. For the purposes of this section, the term ''wages'' shall not include that part of remuneration which, after remuneration equal to the unemployment insurance taxable wage base with respect to employment with such employer has been paid to an individual during any calendar year, is paid to such individual during such year; provided, however, if the amount specified in the definition of ''wages'' in the federal Unemployment Tax Act is higher with respect to a calendar year than the amount hereinbefore specified, such higher amount shall apply to such calendar year. For the purposes of this section, remuneration shall include any wages earned in another state upon which contributions were required and paid under a similar law.

1. (a) The following words and phrases as used in this section shall have the following meanings, unless the context clearly requires otherwise:

   1. (1) ''Experience rate'', the contribution rate which conforms to the reserve percentage of an employer's account under subsection (i) of this section.

      [Paragraph (2) of subsection (a) applicable as provided by 2014, 144, Sec. 78.]

In addition, an employer who has been assigned a contribution rate pursuant to paragraph (1) of subsection (i), has filed all reports required under this chapter and has paid all contributions, interest and penalties due under this chapter, may make voluntary contributions. Such voluntary contributions shall be paid not later than 30 days after the date on which the division has issued a notice of the employer's contribution rate pursuant to subsection (m) or prior to the expiration of 120 days after the start of the calendar year for which the contribution rates are effective, whichever is earlier. Upon timely payment of a voluntary contribution, the contribution shall be credited to the employer's account balance and that employer shall receive a recomputation of its contribution rate for that calendar year. No voluntary contribution shall be refunded in whole or in part.

All contributions paid by employers shall be pooled and available to pay any benefits required under this chapter. The accounts hereinafter established and maintained are book accounts for the calculation of the contributions to be paid by each employer subject to this chapter.