The Platinum Visa Airpoints Dollar earn rate will increase from $85 to $115 spend, with the account fee (every six months) rising from $75 to $90.
Kiwibank said the adjustments to its credit card rewards were the result of upcoming changes to New Zealand credit card regulations.
This will see new caps on merchant fees, which retailers pay to accept credit card payments.
Standard and Platinum cardholders will also no longer receive complimentary Air New Zealand Lounge eVouchers each year if they spend $30,000.
"We know our customers love credit card rewards. These changes are about making sure we can continue to fairly reward customers for everyday spend while ensuring the viability of our offerings," Kiwibank general manager of retail products Fiona Ehn said.
"As with any changes, we are aware some of our customers may wish to reassess their options. We've written to customers with existing products and there is a full breakdown of the changes on our website. We encourage customers to review the information provided and discuss their options with our team."
Last year the Herald reported that when interchange fee caps were introduced in Australia it watered down the credit card loyalty schemes.
On announcing plans to cap the interchange fee last May, Commerce minister David Clark said New Zealand's merchant service fees, which were unregulated and much higher than in Australia, added significant overhead for retailers who often passed on the cost to consumers through higher prices.
"Reducing the merchant service fees that New Zealand businesses are being charged is a priority for this Government, and critical to the recovery of the economy," he said.
Last month ASB said it had planned to downgrade its credit card rewards scheme, only to backtrack the following day after receiving customer feedback.
Gemma Rasmussen, head of communications and campaigns at Consumer NZ, said many credit card holders can expect a decline in rewards as a result of the regulation change that will see merchants paying a lot less to the banks.
"It's worth anyone with a rewards credit card taking a cold hard look at what their points are equating to in dollar value and considering whether it will continue to deliver value. While chasing points can be tempting, many rewards credit cards come with an annual fee and lofty interest rates if you miss a payment," she said.