The major banks have made some progress over the past 12 months in closing the gap between their retail bank customer satisfaction ratings and their business customer ratings.According to Roy Morgan Research, retail bank satisfaction scores are at an 18-year high, with an average rating of 82 per cent for the 23 banks in the survey.The average rating among business customers is 64.4 per cent.Roy Morgan industry communications director, Norman Morris, said business customers give their banks low marks on issues such as maintaining regular contact and understanding their business. The banks' business relationship managers also received low scores.However, things may be starting to turn around for a couple of the big banks, at least. ANZ's retail bank satisfaction rating was unchanged over the 12 months to May, while its business bank rating rose 3.8 percentage points.Westpac's retail bank rating rose two percentage points over the same period, while its business bank rating rose 2.9 percentage points.NAB's retail bank rating rose two percentage points, while its business bank rating rose 1.7 per cent points. Commonwealth Bank's retail bank rating rose 1.7 percentage points, while its business bank rating was unchanged.Westpac is the outlier among the Big Four in the business bank survey. It has a satisfaction rating of 70.3 per cent, compared with 64.5 per cent for ANZ, 64.1 per cent for CBA and 63.5 per cent for NAB.The bank with the most satisfied business customers is Bendigo and Adelaide Bank, with a rating of 78.1 per cent.