The rate is not available through advisers, and is only applicable for customers who qualify for HSBC Premier accounts. Customers need a mortgage of more than $500,000 or $100,000 in savings and investments.
The rate cut marks the latest in a long line of cuts so far this year. HSBC becomes the cheapest in the market once more, after domestic banks including Kiwibank cut rates below 4%.
HSBC's rate came into effect today, and comes amid a backdrop of falling wholesale rates. Some economists believe the Reserve Bank will cut the OCR in the next 12 months, as the country struggles to achieve significant GDP and inflation growth.