AUD is 4 weeks is very doable, if you understand it. Understanding it is not a matter of having taken lots of courses in it or having done it in work; it's just a matter of understanding the thought process that goes into it. Like, if I say the client's financial show $283m of revenue, and I want you to test it, can you think “If the client is being fraudulent, then is this number likely to be high or low? If it's high, then what would cause that? If it's low, then what would cause that?” That sort of thing is the audit thought process. And…the tricky thing with audit is there's not one right or wrong answer, cause it's a thought-process thing. If your client's motivation is to minimize taxes, then they're likely to be trying to minimize revenue, so the answer to my first question would be “if the client is being fraudulent, then this is likely low”; however, if they're trying to maximize shareholder return, then the answer would be “high”. But the key to audit is being able to follow the thought-process.
For those who the thought-process comes naturally to, you could probably study for a week and pass the exam. The thought process was pretty natural for me. I had one undergrad AUD course (online, no instructor involvement, so basically I read a textbook and did some homework and that was all) and no work experience, studied about 3 weeks around work, and scored above a 90 (can't remember exactly – 92 or 93, something like that). The study was needed to get the lingo down, familiarize myself with the rules, etc., but the thought process was the necessary framework to fit it all into.
However, for others, the thought process isn't natural and trying to “brute force” their way into thinking that way is hard. For those people, 3 weeks wouldn't be enough, and those are the people who put in admirable efforts studying and come up short on exam day.
The only way to know which one you are is to dig into your studying and see how it goes. But give it a shot – 3 weeks for an attempt sounds pretty good. Know that AUD is a real wildcard – most people score either their lowest fail or their highest pass on AUD their first time around, and the people with their lowest fail and their highest pass will both feel the same as the other one walking into and out of the exam. So, give it a try and see what happens! 🙂