Chris , you also will find that these accreditations differ from one client to another ! ie Safecontractor , SSIP , CSCS , ect 
Not forgetting PLI . You may have to increase your premium !
I have had to do my CSCS , IPAF , PASMA , FIRST AID  , 
All of this ,  has to be in place before you are even considered to be approved on their list . 
When approved !!! , you have to be  successful in your quote , RAMS to be approved 
Work within their diagram and initial outlay of Fuel , Labour , Accommodation , Hire Equipment , Utility usage 
Payment 3 month later  
 
 Ed