You will need this registration if you intend to conduct business as a certifying plumber and drainer. Certifying plumber and drainers certify the design and / or construction of plumbing and drainage works in all classes of buildings. They also certify the construction of hydraulic fire services such as fire hydrants and fire hose reels in accordance with the provisions of the Building Code of Australia.
You can apply for this licence as an individual or corporation.
If you are an interstate applicant, you may be eligible to obtain a licence through mutual recognition.