Registered certifiers assess and determine applications for development certificates for building and subdivision work. Certifiers are public officials and independent regulators of development - they don’t work for builders or developers.
They are required to uphold the public interest and can only issue a development certificate if all legislative conditions are met.
Most certifiers are qualified building surveyors who can issue development certificates, be appointed as the principal certifier, and carry out inspections.
Note: A person who may be an accredited certifier, but is acting in any other role than to certify building work, is being engaged as a consultant to the development (e.g. a building surveyor giving consultancy advice during fire engineering brief process).