Leading advisers say banks continue to test customers' borrowing abilities at rates of close to 8%, despite the central bank rate falling by 0.75% since May.
They believe lenders should adapt to the new environment and test borrowers at a more reasonable rate of interest.
Craig Pope, of Pope & Co Mortgages in Wellington, says the "magnitude" of the Reserve Bank OCR cut could lead to a rethink from the banks.
"I think the banks will start to look at that and ask 'is it fair?' Given the OCR has dropped, I'd think that would be high on the radar for banks."
Pope said some banks had begun to make subtle changes on servicing calculators, but there were no updates on the servicing test rate.
Kris Pedersen, of Kris Pedersen Mortgages, said the servicing rate was a problem and "so far out of whack" with rates on offer. He said long-term rates on offer in the market did not come anywhere near the 8% mark.
"Common sense says the test rates are far too high. There's a massive disparity," Pedersen says. "I don't know where the Reserve Bank sits on that, but the banking system is overly prudent in the way they are doing things at the moment."
Mortgage Supply Company's David Windler said some banks used the floating rate as a guide for their testing rates, but others stuck to other metrics. He hopes banks will "look at the servicing rate and the gap between that rate, and what's available".
The tough servicing tests in the NZ market are widely believed to have been influenced by Australian regulator APRA, which imposed a minimum rate of 7% on Aussie lenders. APRA recently abolished the guidelines, amid signs of a housing downturn in Australia, and a falling Official Cash Rate.
Advisers are hopeful lenders over here will revisit their testing criteria in light of APRA's decision.
"The Australian owned banks have a clear mandate to review this," Windler adds.