NAB was the first having announced late-afternoon on Wednesday, more than 24 hours after the RBA's monetary policy decision was announced. NAB was also the first to fire the shot in March.

It was business as usual for NAB, increasing variable-rate mortgages and some savings products by 25 basis points. 

AMP chief economist Dr Shane Oliver provided several reasons as to why banks might be slower than in the past to announce rate changes.

"It can vary from almost same day to sometimes a few days. Maybe they wait around for one to go first and it took longer for one to move this time," Dr Oliver told InfoChoice.

"Maybe it's because of increasing borrower angst about rate hikes.

"If anything given the increasing pressure on their margins you would think they are under increasing pressure to pass on cost of funding increases."


Here's a breakdown of some other movement and the approximate times (AEST) at which they announced, accurate to the time of writing.

The below increases apply specifically to variable-rate home loan products, with more mixed results for savings products.

AMP

AMP appeared to be the first on Thursday to fire the shot, which is unusual given the major banks usually move first.

  • Increase: +25bps
  • Effective: 5 May for new customers, 8 May for existing
  • Announced: 4 May, around 9am AEST

AMP reportedly also sent out the notice first to institutional newsletter clients, rather than home loan customers.

ANZ

  • Increase: +25bps
  • Effective: 12 May
  • Announced: 4 May, 12.45pm

Athena

The non-bank lender did not beat around the bush.

  • Increase: +25bps
  • Effective: 4 May
  • Announced: 4 May, 1pm

Westpac

  • Increase: +25bps
  • Effective: 16 May
  • Announced: 4 May 2.30pm

At the time of writing, that leaves CBA holding the bag as the only major not to announce.

Keep in mind due to responsible lending obligations, the interest rate increases are not actually reflected in repayment increases until around 21 days after the 'effective' date.

In that three weeks, customers will likely be paying more of their total repayment towards interest.