The big four have been slammed for not passing on rate cuts in full (Getty).
Australia's big four banks copped a lot of flak in 2012 for failing to pass on interest rate cuts in full, but the controversy did little to hurt their popularity with business customers.
The monthly DBM Consultants Business Financial Services Monitor (BFSM) shows the banks - the Commonwealth Bank of Australia (CBA), National Australia Bank (NAB), ANZ and Westpac - either maintained or improved their satisfaction ratings with customers in 2012.
Westpac remained in first place in December, retaining the same satisfaction rating - 7.5 out of 10 - it had 12 months earlier.
Commonwealth lifted 0.1 points between December 2011 and December 2012, to finish the year with an average rating of 7.4.
ANZ retained its satisfaction level of 7.0, but fell to equal last place alongside NAB, which lifted its rating from 6.9.
The banks maintained their satisfaction ratings despite regularly attracting criticism for failing to pass on in full Reserve Bank of Australia interest rate cuts.
The RBA has cut the cash rate 1.75 percentage points since November 2011.
Over the same time, Australian banks have reduced their standard variable mortgage rates by an average of 1.35 percentage points.
DBM managing director Dhruba Gupta said banks tended to maintain or improve their satisfaction ratings during times of economic uncertainty.
"The bank is often the first port of call for a business that may be struggling and needs to increase their overdraft or increase their debt levels," he said.
"I think the banks are also realising that a major point of difference for them is customer service and they are putting more resources behind this."
Large business customers (those with turnovers greater than $50 million) were the most satisfied with their bank, with CBA's satisfaction rating of 7.8 leading the pack in that category.
Satisfaction with all four banks grew or remained steady among small businesses (with turnovers of up to $5 million), during the year, but both ANZ and Westpac suffered a decline among medium-sized businesses (with turnovers between $5 and $50 million).
ANZ also suffered a fall in satisfaction among micro-business customers.
The BFSM tracks the satisfaction rating of the big four banks through interviews with 20,000 business customers annually.