Chris, you don't need to have a NVQ to get ACS. To Mohammed, as Chris said, you will only get tech cert, so would need to pay another 1600 or so for NVQ and find somebody to do your NVQ portfolio with, which will take another year or so. They planned to merge tech cert and NCQ together so people enrolling on course had to have an employer in order to success. Tech cert itself gives you no experience just some plumbing knowledge. I don't know what happened, if they merged or just renamed courses. Maybe different colleges offering different stuff, but this would be so confusing to people, as in my opinion, it should be same throughout whole England.
I would suggest, if you not over 24, to find somebody who will take you on and get some experience, you can then enroll for NVQ and finish your portfolio. I think you should be able to enroll anytime, as long as college have somebody to check your portfolio.