I am planning to get laser hair removal. Is there a difference between clinics where you are asked to shave yourself and those that don't?

While researching laser hair removal, I noticed that some clinics require you to shave before the procedure, while others don't. I'm wondering if there is actually a difference. I'm worried that shaving myself might irritate my skin, and I'm not sure which method is better. If anyone has experience with this, could you please let me know?