It depends on the utility. Some only let you take the test every 90 days, some every 30 days. Most only let you take it a certain number of times, 3 comes to mind for my utility.
How about this? I understand preparing for the worst & knowing options. Take a look through that section. Don't look just at the practice tests, but also at the experiences that others have posted throughout that section. Use that great resource to start working right away to prepare for a successful test result and your future.
It sounds simple and I do realize that it's not. 14 years into my career my job was cut and with little prep I had to retake the POSS test along with a co-worker who hadn't taken it in almost 30 years. We both passed & I think you can too. The biggest key is practice, practice, practice. (a little self-confidence helps too!

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Pass off that failure as a mulligan knowing that you can do better. If you run into questions don't hesitate to ask them. You'll be expected to do some research first, but if you're willing to do some work there are people who will be more than happy to offer help & hints right here!