​KRS 342.122(2)(b) Beginning on January 1, 2020, all assessments shall be electronically remitted to the funding commission quarterly not later than the thirtieth day of the month following the end of the quarter in which the premium is received. Receipt shall be considered timely when filed and remitted using the appropriate electronic pay system as prescribed by the funding commission. Employers carrying their own risk and employers defined in KRS 342.630(2) shall pay the annual assessments in four (4) equal quarterly installments.

E-File/E-Pay can be accessed here.
Additional information on the calculation of the Special Fund Assessment can be found here.