Ribbon?

Buying wholesale may not be the best, depending on what you want. It depends on whether you require precise colours or will assorted colours be ok, what kind of quantities and qualities you want. By the time you have jumped through all the hoops of quantities and deliveries and VAT and invoices and minimum purchases you might well find that a bit of hunting round will get you what you want through retail sources.

It will probably involve a bit of slogging though websites, but in the meantime http://www.minervacrafts.com/sewing-ribbon/ might be a place to start.

Have you tried just googling 'wholesale ribbon'?

This http://www.meiflower.co.uk/satin-ribbon-10mm/ came up as practically the first item when googled.