When do I pay for survey?

[Mumsywumsywoo]

So the survey is £500. If I instruct the surveyor to carry this out on Wednesday do I pay her on Wednesday or do I pay when the report is ready?? I want to get the ball rolling with the survey but I won't have £500 until about 2 weeks time...

I think when you instruct

Our surveyor released the report after we'd paid.