Well, in general, it is possible to use the present simple and the present perfect simple interchangeably after the conjunctions 'when', 'as soon as', 'until', etc., e.g.
We'll come as soon as we finish.
We'll come as soon as we have finished.
However, you DON'T USE the present perfect if two things happen together. Cf.
When I phone Mary, I'll ask her about the price.
Kiedy będę dzwonił do Marysi, zapytam się jej o cenę.
NOT
When I've phoned Mary, I'll ask her about the price.
Kiedy (już) zadzwonię do Mary, zapytam się jej o cenę.
Remember: if you use the present perfect, one thing MUST be complete BEFORE the other (so the two things DO NOT HAPPEN together). Cf.
When I've phoned Mary, we can have lunch. (= First I'll phone Mary and after that we can have lunch, not at the same time!)
Hope that you got it a bit.