REAA chief executive Kevin Lampen-Smith said the changes were designed to further protect buyers and sellers.
While complaints about agent behaviour have dropped slightly in the three years since the legislation was introduced, the Authority fielded 807 complaints last year.
On average, 12 complaints are received each week, mostly about marketing, incompetence, negligence, non-disclosure and undue pressure issues.
Less than half of those progress to the complaints assessment committee.
Key changes
Agents must explain to clients when an agency agreement will end and recommend parties seek legal advice before signing an agreement.
Agents must explain to clients in writing when there is no comparable or semi-comparable sales data to base an appraisal on.
Agents have to explain to a prospective client that how they choose to sell their property can impact on the benefits the agent receives.
A new rule designed to help protect sellers from the risk of paying two commissions and new rules for buyers' agents.