Failure by vendors to disclose information about issues with a property to buyers is a key problem.
The authority aims to resolve 90 per cent of all complaints within a year but it only achieved 88 per cent on that measure.
Revenue from agents being fined was below budget "due to the impact of Covid-19 and a lower number of complaints received", notes to the annual accounts showed.
The Real Estate Agents Act was passed by a Labour-led government in 2008, removing disciplinary powers of industry lobby group the Real Estate Institute.
The authority said the latest numbers were 37 per cent down on 10 years ago, when it was established to regulate the sector.
Denese Bates, chair of the authority's board, said New Zealand now has 15,520 real estate licensees, 367 more than last year.
Some licensees used the lockdown period to completed professional development requirements. Training rates rose 265 per cent in April this year compared to last April.
Bates said the drop in complaints reflected the authority's work to lift professional standards and put more focus on early intervention to resolve issues before they became complaints.
"The authority has worked hard to support high standards of conduct for licensed real estate professionals through our continuing professional development programme, improved guidance and by responding to a high number of enquiries from the sector," she said.
"The reduction in complaints shows that this work is having a positive impact," she said.
Belinda Moffat, new authority chief executive, said more buyers and sellers consider agents to be professional, well-regulated, well-monitored and fair.
"Buyers and sellers of property deserve to feel confident that there's a regulator out there
setting a robust minimum standard for conduct, training, and expertise for real estate work," she said.
Of the 288 complaints made, 82 resulted in a finding of unsatisfactory conduct or misconduct against the licensee. This equates to less than one per cent of the 15,520 professionals who hold an active real estate licence.
Bates got $31,000 in board fees, up on last year's $20,000.