I still don't understand what the problem is.
If and it's a big IF, the windows are wrong then it is stil up to your guy to sort even if you pay for them direct, all he is asking you to do is pay for them direct, whatever the reason maybe, it still speeds the payment process up and as it has already been said, if you pay for them by credit card any problems and you can get the money from your c/c company.
Don't be worried about any reasons why other customers may not have paid your fitter, that could judt be down to people not wanting to pay for what ever reason.
If you are happy with the work he has done for you in the past, then just do as he is asking and get the work done.
You may find that you put this guy off, waste time looking for someone else and then they ask you for the same terms, but you wont know who they are.
Rico
If and it's a big IF, the windows are wrong then it is stil up to your guy to sort even if you pay for them direct, all he is asking you to do is pay for them direct, whatever the reason maybe, it still speeds the payment process up and as it has already been said, if you pay for them by credit card any problems and you can get the money from your c/c company.
Don't be worried about any reasons why other customers may not have paid your fitter, that could judt be down to people not wanting to pay for what ever reason.
If you are happy with the work he has done for you in the past, then just do as he is asking and get the work done.
You may find that you put this guy off, waste time looking for someone else and then they ask you for the same terms, but you wont know who they are.
Rico