Payment gateway integration
We connect bank link, card and other online payments so that order statuses match real payments and refunds are easy to process.
How payment gateway integration works
Payment gateway integration means your website or e-shop can safely accept money from a buyer and then correctly know whether the payment went through. For the buyer, it looks like a few seconds in a payment window. Behind it, you need a clear order status, an invoice and the option to refund.
Three kinds of business owners usually look for this service: those who are just starting to sell online, those who want to switch payment provider, and those whose payments are already connected but statuses tend to get mixed up. The buyer has paid, but the order shows «awaiting payment», or the other way round.
KVANTS is a small studio where two people plan and build projects themselves. We help you choose a suitable provider, connect it, and test every payment method before the site starts working with real money.
What buyers expect at checkout
Buyers want to pay the way they are used to. If their usual method is missing, some leave without completing the order. So payment integration for an e-shop starts with a question: who are your customers and how do they pay?
Bank link payments
For many local buyers, bank link payments are the first choice. Providers offer several banks through one connection, and the buyer should see a clear list of banks.
Card payments
Visa and Mastercard are needed for both local and international buyers. In the European Union, card payments are additionally confirmed with 3-D Secure, in line with PSD2 requirements.
Apple Pay and Google Pay
These methods let people pay with a couple of taps on their phone. In most cases they appear once card payments are activated and the platform supports them.
Pay later
Some providers let buyers split a payment or pay later. This can help with more expensive goods.
Payment links
If you have no shop, an invoice can be paid by sending the customer a link or QR code. This suits service providers and one-off deals.
Montonio, MakeCommerce, Klix or Stripe
There is no single right answer. The choice depends on your customers (local or international), your platform, the methods you need and each provider's fees. We compare the fees with you, based on how you sell.
Montonio integration
Supports payments from popular banks in Estonia, Latvia, Lithuania and Poland, cards, «pay later» options, payment links and QR codes. Apple Pay and Google Pay appear after card payments are activated on supported platforms such as WooCommerce, Shopify, PrestaShop, Magento, OpenCart and Shopware, as well as in custom integrations.
MakeCommerce
Offers Latvian bank payments, including Swedbank, SEB, Citadele and Luminor, as well as Revolut, N26 and Visa/Mastercard cards. Apple Pay, Google Pay and Click to Pay switch on together with card payments. Card details are entered in the provider's iframe, so they never reach the shop's system. The same module can also connect delivery, such as Omniva, DPD, Venipak, Unisend or Smartposti.
Klix
Klix from Citadele provides cards, Apple Pay, Google Pay, Click to Pay and payments from the largest Baltic banks through one integration. There is also Klix Pay Later, which lets buyers pay for a purchase later.
Stripe integration
Suited to selling abroad and to SaaS products. Supports cards worldwide, subscriptions and recurring payments, and refunds through the API and webhooks. PayPal can be added as an extra method for international buyers.
Statuses, webhooks and refunds
This is the part that breaks most often. A buyer pays in their bank but closes the browser without returning to your shop. If the order status depends only on the return page, you will not find out.
So we use the provider's notifications (webhooks, or callbacks), which tell the server the payment result regardless of the buyer's browser. Each status has its own logic: awaiting payment, paid, failed, cancelled, refunded. If a notification arrives twice, the system processes it only once, so there are no duplicate invoices or emails.
- the order status updates even if the buyer closes the page
- protection against processing the same payment twice
- full and partial refunds from the admin panel, where the provider supports it
- passing orders to your accounting system or e-rēķini (structured e-invoices) flow, as described on the automation page
- email notifications to the customer and to you
Ready module or custom build
If you use WooCommerce, Shopify, PrestaShop or a similar platform, you can often use the official module. It is faster and easier to maintain. We install it, set up the statuses and adjust the checkout page.
If your website or web application is custom-built, we connect payments through the provider's API. This allows subscriptions, invoice payments or non-standard order logic. If you are building a new shop, this can be done together with the e-shop development.
Security and testing
We do not store card details. They are entered in the provider's secure environment and never reach your server. The site works only over HTTPS, and we keep API keys in a safe place, not in publicly accessible code.
Before launch, we try each method in test mode (sandbox): a successful payment, a cancellation, an error and a refund. We also check on a mobile device, because many buyers pay from their phone. After launch, we track failed payments so problems are spotted in time.
What's included?
advice on choosing a provider based on your customers and platform
connection to an official module or an API integration
setup of bank link and card payments
Apple Pay and Google Pay setup, where the provider supports them
webhooks and correct order statuses
protection against duplicate payment processing
full and partial refunds, where the provider supports them
checkout page usability improvements
sandbox testing on desktop and mobile
monitoring of failed payments after launch
Why choose us?
Full cycle
Development, design, hosting, email, maintenance — all in one place. No need to coordinate multiple vendors.
Own infrastructure
Client projects run on our servers with 24/7 monitoring. We catch issues before your visitors do.
Clear pricing
A development plan before work starts and a fixed project price. No upfront payment for small jobs.
Direct contact
You talk directly to the developer, not a project manager. Faster decisions, fewer misunderstandings.
How we work
Short conversation
We find out what you sell and to whom, which platform you use and which methods you need.
Choosing a provider
We compare suitable options and help you prepare the application to the chosen provider.
Written plan
You receive a plan and quote showing the scope of work and timeline.
Setup and testing
We install the integration, set up the statuses and try every method in the test environment.
Launch and monitoring
We switch to real payments, make a check payment and watch for failed transactions.
Frequently asked questions
Which payment provider should I choose?
It depends on whether you sell to local or international buyers, which platform you use and which methods you need. The provider's fees and contract terms also matter. We help you compare and recommend the most suitable option.
Can I use several providers at once?
Yes. For example, you can have one provider for local buyers and Stripe or PayPal for international ones. What matters is that checkout stays clear for the buyer and order statuses are handled the same way.
Does it work with WooCommerce, Shopify or a custom site?
Yes. Many providers have official modules for popular platforms. For custom sites and web applications, we build the integration through the provider's API.
What if a buyer paid but the order shows unpaid?
This usually happens when the status updates only when the buyer returns to the shop. We use webhooks so the server receives the result from the provider regardless of the browser. We can investigate and fix existing cases.
How do refunds work?
If the provider supports refunds, you can make them from the shop's admin panel, including partial ones. The order status updates and, if needed, a credit invoice is prepared.
Do I need a contract with each bank?
No. Providers combine several banks and methods in one connection. You sign a contract with the payment provider you choose, not with each bank separately.
Are card details stored on my site?
No. Card details are entered in the provider's secure environment and we do not store them anywhere. Only order and payment status information stays on our side.
Can I accept payments without an e-shop?
Yes. Some providers offer payment links and QR codes that you can send to a customer by email or message. This works for services and one-off invoices. If needed, the links can also be connected to your web application.
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