The new one year special is the same price as BNZ and Kiwibank's one year offering, behind only ANZ as the cheapest in the market at 3.05%.
Westpac's one year drops 30 basis points, and its two year special drops to 3.39%, a cut of 16 basis points.
The changes will come into effect on Tuesday March 24.
Banks have slowly begun to drop rates after the Reserve Bank cut the OCR by 75 basis points last Monday.
Westpac NZ general manager of consumer banking and wealth Gina Dellabarca said the cuts were designed to support borrowers in the Covid-19 crisis.
“We urge people who are concerned about their finances to contact us to discuss their options, which can include mortgage holidays, or temporary interest-only payments on their mortgages,” Dellabarca said. “We’ll be announcing additional support initiatives in the near future.”
BNZ's 18 month rate at 3.05%, effective today, is the joint-cheapest on the market.