Australian businesses are more satisfied with the big four banks than at any point in the last four years.

But satisfaction levels for National Australia Bank and ANZ continue to lag behind Commonwealth and Westpac.

The big four had an average rating of 7.3 out of 10 in August, according to the DBM Consultants Business Financial Services Monitor (BFSM).

It was the highest average satisfaction rating in the four year history of the BFSM.

“The figures for most of the major banks, not just the Commonwealth Bank, have risen since our research started four years ago,” DBM Consultants Director Maria Claridad said.

The Commonwealth had the highest rating in August, with an average score of 7.6 out of 10, followed by Westpac on 7.4 out of 10.

Meanwhile, ANZ and NAB continued to lag behind on 7.0.

The BFSM surveys more than 20,000 businesses annually.