Exams with different training providers

Hello I'm new to the forums and just wanted advice on something.

I unfortunately failed an exam a couple of weeks ago but feel ready to retake as soon as possible now. My training provider's next available exam dates are in a month's time but I'd really like to retake my exam soon as I have been revising and feel much more confident. I have also now started a new module and would like to concentrate on this without having the previous module hanging over me for another month.

My question is, if you are with a certain training provider for a classroom course do you have to take all your exams with them? Can you sit an exam at another training provider's assessment centre? There is a different assessment centre in my city that has a lot of available exam dates. I just wondered if there was a rule that you had to sit all exams at the same provider.

Thanks