The Banking Ombudsman Scheme says it has seen complaints about lending delays double since the borrowing rules came into effect.
The Credit Contracts and Consumer Finance Act (CCCFA) requires banks to closely vet mortgage applicants' spending habits and personal finances.
Banking Ombudsman Scheme chief executive Nicola Sladden said it had seen recent increases in complaints about lending, particularly about delays and banks not acting as expected.
Next month, the Ombudsman would release data on banking complaints from October to December 2021.
"It will be interesting to see what issues consumers have raised with banks," she said.
Yesterday, the Otago Daily Times reported that two separate Dunedin women were asked by their banks, before the CCCFA rules came in, if having children was in their five-year plans.
Asked if this was appropriate for banks to be asking, a spokesman for The Office of the Privacy Commissioner said it was important that agencies only collected people's personal information for a clear purpose.
Organisations needed to carefully consider if they needed the information they were asking for because the amount and type of personal information that needed to be collected could differ in different contexts, he said.
The Council of Financial Regulators is at present investigating whether the CCCFA rule changes are being implemented as intended.