When it comes to the major bank with the highest satisfaction rating among business customers, you can pretty much take your pick. There are three surveys and each one gives the gong to a different bank. Only ANZ misses out.Roy Morgan Research issued its monthly Business Satisfaction survey last week, with Westpac holding the top spot by a wide margin. Its satisfaction score was 67.9 per cent, compared with 63.9 per cent for Commonwealth Bank, 63.3 per for National Australia Bank and 60 per cent for ANZ. Westpac has been the top rated business bank in the Roy Morgan survey since August 2011.DBM Consultants' latest Business Financial Services Monitor gave Commonwealth Bank the top rating among large, medium and small businesses. Micro businesses gave the highest rating to Westpac.At a client briefing in Sydney last week, East & Partners said NAB was the highest rated major bank in its Business Banking Index and was the only major bank whose satisfaction rating was going up.DBM's ratings are based on 20,000 interviews a year, Roy Morgan interviews 2500 businesses a month and East & Partners conducts 10,200 interviews with business banking customers every year.It is hard to pick the differences in methodology, but one is that East & Partners does not survey micro businesses. Its sample covers businesses with an annual turnover of over A$5 million.ANZ chief executive Mike Smith must be hoping a fourth survey company enters the market.