Australia’s big four continue to lag behind other lenders in terms of home loan customer satisfaction, according to new research.

The overall satisfaction level of the big four’s home loan customers in the six months to September 2015 was at 80%, while for the next seven major banks the overall was 85%.

The data, from Roy Morgan’s Single Source survey, discovered that ME Bank and ING Direct are the leaders in home loan customer satisfaction.

ME Bank’s home loan customers posted the highest satisfaction level, at 92.8%, while ING Direct took 92.7%. Bank SA could barely keep up as runner-up with 88.7%, and Bendigo Bank was not far behind at 87.6%.

Of the four big banks, CBA was the leader with 82.0%. Westpac followed with 80.8%, NAB was at 78.9%, and ANZ posted 77.5%. While they reduced their home loans rates over recent years, ANZ, CBA, and NAB all have home loan customer satisfaction levels lower than that of their non-home loan customers.

Westpac alone has home loan customers who are more satisfied than their other customers, at 80.8% versus 79.8%, respectively.

In terms of overall satisfaction, CBA took the lead among the big four with 82.5%, improving by 1.4% points in September—the biggest improvement of the four. NAB came next with 81.4%, rising 0.6%.

Both ANZ and Westpac, however, took hits to their overall satisfaction levels, down 0.3% and 1.0% points, respectively.

While CBA showed marked improvement over the last year, the lender still struggles against the average posted by the other banks outside of the big four, with an overall satisfaction level of 86.7% in the six months to September.

The big four all improved in satisfaction levels over the last year, by 0.5% points. The smaller banks, in comparison, improved even more. Teachers Mutual took the top spot at 95.3%, rising by 5.2% over the year. Next was Bendigo Bank at 89.9%, up 2.0% points and Bank SA was at 87.7%, up 4.3% points. Bank of Melbourne was at 87.0%, up 5.8% points.

The CBA once again leads the big four, this time in terms of main financial institution satisfaction in September, at 84.4%. The bank also displayed the biggest improvement over the last 12 months, by increasing up to 2.0% points.

“With signs beginning to emerge that home loan rates will rise, it will be of critical importance to track how mortgage customers feel about their bank as it is likely to adversely impact on key metrics such as satisfaction and advocacy,” observed Roy Morgan Research industry communications director Norman Morris.

“We have seen in the past that if increases in home loan rates are given a great deal of adverse publicity, then a decline in customer satisfaction inevitably follows,” he added.