Payment Gateway Integration in New Zealand

Keep the card numbers away from your servers

This is the first decision, it is worth more than the rest combined, and it is not a technical preference.

Modern gateways give you two safe options. A hosted payment page sends the customer to the gateway to enter their card. Embedded fields put the gateway's own inputs inside your page, so it looks like your site but the card data goes straight to them. In both cases the number never touches your infrastructure.

The alternative — accepting card details on your own server and passing them on — makes you responsible for a substantial and continuing compliance obligation, and makes any future breach dramatically more expensive. There are businesses that need it. Yours almost certainly does not.

Ask every developer quoting: will card numbers ever touch our servers? The right answer is no, without hesitation.

Choosing a gateway in New Zealand

Stripe is the fastest to develop against, has the best documentation by a distance, and covers cards, wallets, subscriptions and payouts in one place. For most businesses it is the sensible default, and the reason many quotes will assume it.

Windcave is a New Zealand company with deep local bank relationships. It is a strong choice if you also take payments in person and want one provider across your terminals and your website.

Worldline, previously Paymark, sits behind a large share of New Zealand card processing and often turns up when the bank drives the decision.

On modest volumes the difference is convenience rather than money. Once you are processing a few hundred thousand a year, the rate becomes negotiable — many businesses never ask, and pay the published price for years.

Work out the real cost, not the headline rate

Ask each provider what your actual mix would cost, and make sure the mix includes:

• Domestic cards, which are the cheapest.
• International cards, which are not, and which many New Zealand businesses take more of than they realise.
• Amex, if you accept it.
• Currency conversion, if you sell overseas.
• Refunds — some providers keep the fee.
• Chargebacks, which carry a fee whether or not you win.
• Payout timing, which is a cashflow question rather than a cost.

A quarter of a percent looks trivial and is $2,500 a year at a million dollars.

The failure that costs you customers

Here is the scenario every experienced payments developer has seen:

The customer enters their card. The bank approves it. The money leaves their account. Then your website times out, or the browser is closed, or the phone loses signal — and your system never records the payment.

The customer has been charged and has no order. They ring you, and you have nothing to look at.

Handling this well requires two things. Webhooks: the gateway notifies your system independently of the customer's browser, so the order is created even if they walked away. Reconciliation: a scheduled job that compares the gateway's record of the day against yours and flags every mismatch to a human.

Ask each developer how they handle this specific case. It is the clearest signal in the whole quoting process, and the answers will not be similar.

Refunds are not a mirror image

Almost every brief describes taking money and forgets giving it back. Then a customer wants half an order refunded and someone is logged into the gateway's dashboard doing it manually, with nothing recorded in your own system.

Settle these while quoting:

• Who in your team can issue a refund, and up to what value?
• Are partial refunds supported, and what happens to the fees?
• Does the refund flow back into your accounting automatically?
• What does the customer receive, and how quickly does it reach their bank?

Add payment methods on purpose

Apple Pay and Google Pay are cheap to enable through a modern gateway and measurably improve mobile conversion. Buy-now-pay-later lifts conversion on discretionary purchases and costs 4 to 6 percent, so whether it pays depends entirely on your margin. Account-to-account payments are far cheaper per transaction and are worth a look for higher-value or repeat purchases.

Every method you add is another path that has to be built, tested, refunded and reconciled. Two done properly beats five done hopefully.

Comparing five quotes

Quotes here are often close on price and far apart on what happens when things go wrong. Read for:

• Who confirmed, unprompted, that cards would not touch your servers?
• Who mentioned webhooks and reconciliation before you asked?
• Whose quote includes refunds, not just payments?
• Who asked what happens to the money in your accounting system afterwards?
• Who has integrated the specific gateway you are considering, recently?

Describe what you are charging for, whether it is one-off or recurring, which gateway you use now if any, and roughly what you process a year. Developers who do this work regularly will tell you within a paragraph whether you have a $9,000 job or a $40,000 one.