As the market awaits ANZ's promised rate decision this Friday, NAB has vowed to beat its fellow majors on rates for the remainder of 2012, regardless of moves by the RBA.

Due to a quirk in the calendar this month, ANZ's promise to decide its interest rates on the second Friday of the month mean it may have to declare its hand before the other majors following yesterday's RBA meeting.

However, NAB made its own splash in the market yesterday by promising to price its standard variable rate below that of the other majors for the remaining 11 months of 2012.

NAB Group executive of personal banking Lisa Gray said the bank would commit to maintaining the lowest standard variable rate.

"For 2012, NAB is committed to having the lowest standard variable home loan rate of the major banks," Gray said. "This commitment is available to all existing and new home loan customers on NAB's standard variable rate products."

The promise came as banks aside from just ANZ have increasingly flagged that their funding costs are no longer correlated to the official cash rate.