Payment gateway
A payment gateway is the service that securely transmits payment details from a website to the systems that authorise and settle the transaction.
In full
A payment gateway captures payment details on a website and passes them securely to the acquiring bank and card networks for authorisation. In New Zealand the market has a structure that surprises overseas merchants: local gateways such as Windcave typically require a separate merchant facility from your bank, so the gateway fee and the bank's merchant service fee are distinct charges. Providers such as Stripe act as both gateway and acquirer with a single published rate. Bank transfer options including POLi and Account2Account are also available and are usually cheaper than cards on larger transactions because their fees are capped.
Why it matters
Gateway choice affects both cost and checkout experience. It also affects integration effort, since some New Zealand banks require a hosted payment page and mandatory 3D Secure enrolment.