Satisfaction levels among the personal customers of Australia's major banks reached an 18-month high of 82.0 per cent in April, according to the latest Roy Morgan Research Consumer Single Source survey.But the Big Four banks' personal customers' overall level of satisfaction (80.7 per cent) was well above the level of the banks' business customers (65.8 per cent). In the six months to April 2014, the CBA showed the highest satisfaction level for personal banking customers with 82.6 per cent while Westpac had the highest satisfaction among business customers with just 68.7 per cent.All four major banks showed the same patterns, with lower levels of satisfaction for business customers compared to personal customers. The biggest gap was at NAB, where business customers' satisfaction levels with their main transaction bank were 17.4 per cent points below that of personal customers.The improvements  in the ratings of ANZ, CBA and Westpac were largely a result of home loan customers reacting to reductions in home loan rates, Roy Morgan suggested.Businesses showed very low satisfaction with transaction and deposit accounts, loans and relationship managers or business bankers. NAB scored lowest for accounts and relationship managers, while CBA came in last for satisfaction with loans."Recent moves by the major banks to show an increased focus on the business customers obviously stems from a realisation that something needs to be done to attract and retain them to compensate for the reduced prospects for growth in the personal market," said Norman Morris, industry communications director for Roy Morgan Research."Banks recognise the need for personal contact with their business customers, but at this stage the satisfaction level with [relationship] managers is less than 70 per cent for each of the four major banks. This is an area that obviously needs some improvement if overall satisfaction is to increase."The current Financial System Inquiry will need to consider how well the needs of business are being met by the banks in order to ensure that they remain viable and contribute to economic growth. At the present time it appears that there is room for improvement."