Westpac's decision in December to add 20 basis points to home loan pricing, on top of a 25 basis point increase in the official cash rate, is still biting at the bank's customer satisfaction rating. The rating fell to 70.8 per cent in May 2010, monthly data compiled by Roy Morgan Research shows. This is the first time since February 2001 that Westpac has scored the lowest rating of the majors. Over the 12 months to May, Westpac was the only major bank to show a decline in satisfaction (down 1.5 percentage points). The key driver is a decline of 4.7 percentage points in the satisfaction of its home loan customers, no doubt alienated by the bank's home loan pricing shift announced in December 2009.Those who treat Westpac as their second or third bank take a more sceptical view than the typical customer.For customers where Westpac is not the main financial institution - around one third of all personal customers of the bank - the satisfaction score is 63.6 per cent, and better, just, than the similarly subdued ratings of Commonwealth and National banks.Norman Morris, industry communications director of the research firm, wrote in an email: "All banks have a lower satisfaction level for their non MFI customers by a considerable margin, generally around 10 per cent lower."Yet they represent around 30 per cent of the customer base for each bank. With a lower share of wallet, these customers actually represent the greatest cross sell potential for banks."