Overall customer satisfaction with the big four banks slightly improved in September, up 0.1 per cent to 79.8 per cent, with non-home loan customer satisfaction levels going up by 0.1 per cent and home-loan customers' satisfaction remaining unchanged at 75.9 per cent, according to Roy Morgan Research.
The study showed that this level was well above the long-term average and was not far from the 20-year high (82.9 per cent) recorded in 2015.
Last month, CBA posted the biggest improvement in the level of satisfied customers among the ‘big four', showing a growth of 0.6 per cent. ANZ and Westpac declined by 1.11 and 0.3 per cent points respectively, while National Australia Bank (NAB) improved its customer satisfaction level by 0.1 per cent.
Among the banks outside of the big four, the best performer for customer satisfaction was Victorian Teachers Mutual Bank (95.3 per cent).
Mortgage customers dragged down customer satisfaction levels across all four major banks.
While there were some signs of closing the gap among CBA and NAB customers, ANZ and Westpac's home-loan customers and their level of satisfaction were falling further behind.
On the other hand, Bendigo Bank had the highest home-loan customer satisfaction of the 10 largest customer banks (94.3 per cent) while CBA registered the highest home-loan customer satisfaction of the big four with 77.7 per cent.
Roy Morgan Research industry communications director, Norman Morris, said: "It is a positive sign that despite the high-profile negative publicity surrounding the recent banking inquiry, the big four banks have in fact increased their customer satisfaction levels over the September quarter".
"Having been measuring bank customer satisfaction for over 20 years, Roy Morgan can say that customers currently have a generally positive view of their own bank and, contrary to much of the short-term negative reporting, there has been a solid upward trend over the last 15 years.
"Although home-loan customers have historically had lower satisfaction than other customers, it is surprising that this is still the case given the very low loan and deposit interest rates that favour borrowers."