National Group referees worked part-time, usually alongside another occupation. PGMOL offered weekend matches through software, normally on the preceding Monday. A referee could decline, although PGMOL would typically ask why.
After accepting, either side could still cancel before the referee arrived at the ground. If the match went ahead, the referee officiated, submitted a match report and received a fee. The annual arrangement did not require PGMOL to offer a minimum number of matches or the referee to accept them.