And it costs a lot of money.
Obtained iso9001 for a council I worked for there is a lot of work involved.
I would say it would impress huge companies and make your company stand out but I would say don,t bother unless your comany is huge.
They audit you as well and you have to pay yearly, not cheap.
I would say Safe Contractor proves to your customers that you care and have the right info in place.
Regards Robbie.