My chapter pays for assignors out of dues. Most chapters I know require pay up front. I believe Dayton Ref's chapter requires an up front payment of a certain amount before any assignments are made. Those are deducted and when the ref gets close to using it up they are asked to make another payment. If there isn't any money in the ref's account, they don't get games. They used to do post-season pay and too many refs didn't pay.
That was a problem a couple of years ago. The chapter ran a deficit of ~$3000. Now you pay up front and the deduct from your balance weekly. Below $X you don't get new assignments, below $Y your current assignments are taken away. My first year they only updated my balance twice during the regular season. That was quite a shock when all of a sudden I owed the chapter $20 when my previous one was $75 in the green.
I guess I should consider myself fortunate. My understanding here is that the assignors have contracts with the individual school systems and receive their assigning fee directly from those districts (presumably at the end of the season). The referees are not involved in that transaction at all.
We get a bill generated by Arbiter. We have until December 1 to pay it. If it is not paid by then, we are fined by our association. If we don't pay by the next season, we don't get any games.
Interesting that they find the guys willing to do that. I guess every metro and county are different in how they handle refereeing. I thought our fees were gracious but some of you guys are paid really well for HS