Any participating county, county hospital, city or town, conservation district, or circuit engineering district or trust shall contribute to the System all required retirement contributions due on a monthly basis. All required contributions and supporting documentation must be received by the System on or before the fifteenth (15th) day of the month following the month for which the contributions are due. Any non-state agency employer who remits contributions later thanthirty (30) days following the due date, will be assessed a late charge of three percent (3%). The late charge will be calculated on the unpaid balance and will compound monthly until paid.
Okla. Admin. Code § 590:10-1-7