I know I'm a little late, but it don't hurt.
For grassroots games, which is basically Grade 8's, 7's and the occasional 6 and 5, the refs are paid on-site, or sometimes the system they use is called RefPay. Refs such as myself don't like RefPay though. The one good thing about being a paid official is that you don't get taxed on the income. With RefPay, there IS tax, so we lose money when leagues use RefPay.