Depends on lots of things - is it £100 per month?
If its good paying (on time, no chasing) commercial 5 X
If its residential top notch, close together, well priced monthly with a personal introduction 3 X
If its not been done for months, in two or more seperate locations - - - - ditto - - - - 1 X
If its his rubbish that he wants to ditch walk away!