Colorado works similar to what Billy is talking about. When I moved here from Iowa, in the middle of the season, I had to wait til the next season to get started. I had to take the "new officials" class since I hadn't been previously IAABO certified. Easy class (all rules based), and the test was relatively simple.

Iowa had registration deadlines. I believe the basketball deadline was the first week of December, with late fees assessed for repeat officials who registered later than April of the previous school year. In Iowa, you could be a "temporary" official by taking only the open book test and submitting it by the deadline.

Some leagues would actually allow it. But the best and safest way is still to get a license, that way you can also negotiate with your officiating fee.:D