In a spring marketing gimmick, Commonwealth Bank said yesterday that it "guaranteed" it would beat any "currently advertised rate from ANZ, NAB or Westpac".
The pledge excludes "subsidiaries", which rules out a lot of Westpac's target market through St George, BankSA, Bank of Melbourne and Rams, and may also rule out rate-sensitive customers chasing NAB's low rates offered via UBank.
The limitations in advertised discounts are also ambiguous, for instance, the "up to 0.70 per cent" routinely advertised on the Westpac website. (Discounts advertised by Westpac's other brands are more than this but are already excluded by CBA).
The main catch is the narrow window of time for potential borrowers to respond. The CBA guarantee lasts for little more than two weeks.