Umm I dont believe there is any kind of agreement - it is just a customer / supplier relationship. I think it highly unlikely as the company are based in Dubai, although we do pay a Swiss bank account?
The company in question appear to be charging an interest on late payment - that is what the invoice says - pretty much the same as if it was a UK or European company - so I am assuming (in the absence of a specific contract) that they cannot do this? - Just clarifying! thanks.