I recieved an email today from a local company requesting my bank details so they can make a payment by BACS, the amount £900, around six weeks ago i surveyed and gave them the price, never heard a thing untill todays email, immeadiatly im thinking they want to pay me and i havnt even done the work

, untill i read a little further when i read , they want me to do the work but would like to make payment now as a 10 percent
was offered if invoice paid upon completion, and as their payment run is on the 28th of each month they did not wish to miss out,

so i am providing a proformo invoice ,and yet to arrange date for clean.
WHY ARE MORE COMPANYS LIKE THIS ?
Geoff