Why did the Big Four Australian banks raise interest rates in May 2026?

Commonwealth Bank (ASX:CBA), Westpac (ASX:WBC), NAB (ASX:NAB), and ANZ (ASX:ANZ) raised their rates in direct response to the Reserve Bank of Australia’s (RBA) decision to lift the official cash rate.

When do the new interest rates take effect for CBA, NAB, ANZ, and Westpac?

For the majority of the Big Four banks, including CBA, NAB, and ANZ, the 0.25% increase to home loan variable interest rates will take effect on May 15, 2026. Westpac will also implement its rate hike for new and existing customers on the same date.

How does the RBA rate hike affect Net Interest Margins (NIM) for the major banks?

When banks like CBA or Westpac pass on a cash rate hike "in full" to mortgage holders, it generally supports their Net Interest Margin (NIM)—the difference between interest earned on loans and interest paid to depositors.

Is the rate hike good or bad for bank shareholders?

The news is a double-edged sword for shareholders of tickers like ASX:CBA and ASX:WBC. In the short term, passing on the full hike protects earnings and yield potential by maintaining margins.

How did Macquarie Bank (ASX:MQG) respond differently to the Big Four?

Macquarie Bank distinguished itself by its speed, announcing a full pass-through of the RBA hike just three minutes after the central bank's official statement. While it moved faster than the Big Four in terms of communication, its actual rate changes go live on May 22, one week later than its larger competitors.

What are the deposit rate changes for savers following the May hike?

Westpac (ASX:WBC) was the most explicit regarding savers, announcing that its Westpac Life total variable rate will increase to 5% including bonus interest. Macquarie also confirmed it will offer 5% on savings balances up to $2 million.

How does this news change the investment thesis for the Australian banking sector?

This move shifts the sector's narrative back toward "higher for longer" interest rates, making banks appear more like cyclical plays sensitive to RBA policy rather than defensive dividend anchors. The reversal of last year's rate cuts suggests that inflation or economic resilience is stickier than expected.

Big four banks pass RBA hike to homeowners

Written by Liezl GambePublished May. 5 2026Last Updated May. 5 2026

Australia's major lending institutions—Commonwealth Bank of Australia (ASX:CBA), Westpac (ASX:WBC), National Australia Bank (ASX:NAB), and ANZ (ASX: ANZ)—announced they will pass on the Reserve Bank of Australia’s latest interest rate hike in full.

This follows the central bank's decisive 8-1 vote on May 5 to lift the official cash rate by 25 basis points to 4.35%, effectively returning rates to levels not seen since early 2025 and reversing the temporary relief provided by previous cuts.

CBA led the charge as the first of the "Big Four" to respond, confirming a 0.25% increase for home loan variable rates effective May 15.

Retail banking executive Angus Sullivan acknowledged the mounting financial pressure on households, stating the bank’s focus remains on providing "practical tools and clear guidance" for customers navigating rising living costs.

The trend was rapidly mirrored by NAB and ANZ, both of which matched the 0.25% increase with a May 15 implementation date.

Westpac followed suit, applying the hike to both new and existing customers while simultaneously adjusting deposit rates, lifting the Westpac Life total variable rate to 5% to offer some reprieve for savers.

However, it was Macquarie Bank that moved with the greatest urgency, announcing its full rate pass-through just three minutes after the RBA’s declaration.