when you take on an estate for these developers they give you what they call dockets, postcards with plot numbers on, you get three dockets per plot, one for plasterboarding, one for plastering, one for screeding. as you complete each stage you get the site foreman to sign them and post them of the firm, you receive payment by return of post, once you build up your team,you receive a cheque every day he would have three or foue estates running at the same time. he had this developers work for about 25 years untill he died. he had purchased a small builders merchants to get the material at cost price, and the first delivery every day.