There are plumbing inspectors in the plumbing world and when you lift a consent a plumbing inspector will inspect the work as part of the council sign off.  Only a craftsman - now called "Certifying" plumber has their licence number on the consent.  You can check the status of the person you employ to do the work two ways - one ask to see their licence card and check the date on it to make sure it is current, or go to www.pgdb.co.nz and go to the section "public register" and put in their last and first names and it will tell you if they are licenced (LP = licensed plumber) or CP + Certifying Plumber.  If you get a licensed plumber then they must still be working under the direction of a certifying plumber - i.e. a certifying plumber will instruct them and do final testing.  Ensure you get  a properly licensed person as your house insurance could be void if you do not.  A good way to check who you can trust is to ask friends and colleagues who have used plumbers who they might recommend.  If you are looking at doing gasfitting then you want a plumber/gasfitter if you can - it will save getting to different people the same thing applies (LG = licensed gasfitter and CG = certifying gasfitter).

If you use a Master Plumber then you will also get a Master Plumber Guarantee.  A certifying plumber is someone who has completed an apprenticeship, passed their registration examination, passed their certifying (previously called craftsman) examinations and served at least two years since they were registered.  A licensed plumber has served an apprenticeship, passed their registration examination and got licensed.  They may have worked in the industry for many years, but they have not passed their certifying examinations.  (If you know about sparky's then certifying is just like advanced trade certificate).  You can read more by going to www.pgdb.co.nz which is the regulators website and it talks about employing tradespeople.

Good luck!