NVQ 3

[bmz]

is it right that you have to be working as a childminder for a minimum of 16 hours to be able to book on to do the NVQ3. regards

Not heard that before. Colleges/Course providers may have their own entry requirements though.
What is the full course title and examination board? Is it distance learning?

Newham borough council says their course needs 12 hours work placement.
12 hours to me sounds more likely, than 16 hours.