Overview

To continue using Kustom’s API, you must switch your integration from Klarna endpoints to Kustom endpoints before March 31, 2026.

To verify if you've switched API endpoints go to Kustom Portal (Integrations → API).

Most merchants only need to update the API endpoint.

Only generate new credentials if your integration gets authentication errors after switching endpoints.

Important dates

Deadline: March 31, 2026
If you don’t switch: your API connection will stop working, which may impact checkout and order operations
Downtime: none if you follow the steps below and deploy carefully

What stays the same

API endpoints, parameters, and request/response logic remain the same
Checkout, payouts, and settlement processes remain the same
Customer experience remains the same

What changes:

Your integration must call Kustom API endpoints instead of Klarna API endpoints.

Applicable services:

Kustom Checkout (API)
Kustom Order Management (API)
Kustom Settlement (API)
Kustom Hosted Payment Page (API)
- Payments (API)
Customer tokens (API)

Step-by-step: how to switch

Step 1: update the API endpoint (required)

Locate where your integration sets the API base URL or host.
Replace Klarna hostnames with Kustom hostnames:
- From: *.klarna.com
- To: *.kustom.co
Use the correct base URL for your environment:
- Production: api.kustom.co
- Playground: api.playground.kustom.co
Deploy the change.

Kustom cannot see where in your code or configuration you are calling Klarna. You must locate and update the API host in your integration yourself. This is normally done by a developer or IT team.

If you are unsure where it is configured, ask the person who maintains your integration to confirm that all API calls have been updated from *.klarna.com to *.kustom.co.

Note: the domain ends with .co, not .com.

Step 2: confirm the switch

Your switch is complete when your integration makes a successful request to the Kustom host.

To verify, check the API endpoint switch status page in the Kustom Portal (Integrations → API). It shows which services are still calling Klarna endpoints and the most recent time each host was used.

Note: The status is based on actual API requests. If your integration only calls the API once per day, the Portal will not update until the next request is made. If there is no traffic yet after your change, you may still see "Action required" until the first request hits the Kustom host.

Step 3: API credentials (only if needed)

Do not generate new API credentials unless you need to. Generate new Kustom API credentials only if you get authentication errors after switching host.

Generate new API credentials in the Kustom Portal
Update your integration configuration
Deploy and test again

Testing (recommended)

Test in Playground first
Complete a test purchase to verify your checkout flow
If you do not have a test environment, switch during low-traffic hours and verify production checkout and order flows after deploy
If you have multiple stores or merchant IDs, repeat your changes for each one

If you use a platform integration

If you use one of the platforms below, your platform handles the endpoint switch for you. This means you typically do not need to change the API host in your code yourself. Kustom will coordinate with your platform, and you will be notified when the update is ready.

Platforms that handle the switch for the merchant

Quickbutik AB
Abicart (Textalk Media, Digital Services)
Mystore.no AS
Sincos Software AS
24Nettbutik
MyCashflow
WGR Data AB
Vilkas Group Oy
Bokadirekt AB
Finqu Oy
Norce Commerce
Starweb AB
EG Retail Sweden
Nethit Systems Ltd Oy
Askås I & R AB
Centra Technology AB
eValent
Ny E-handel Sverige AB
TimeCenter AB
Litium Affärskommunikation AB
Visitgroup (Bookvisit)
Visma Webshop
E37 System AB
Kodmyran AB
Abicart AB
Viskan System AB
Salesforce Commerce Cloud (Demandware)
xt:Commerce GmbH
BrinkCommerce
Vendre (Optimizers Nordic AB)
Nordic Web Team
Pulse247 Oy
nopCommerce
ekmPowershop
r360 Resort Systems AB
Majako AB
Omnium AS
Shipmondo

Kustom coordinates with your platform to handle endpoint updates. You will be notified when your platform’s integration is ready.

FAQ

Do I need to generate new API credentials?

Not always. Start by switching the API endpoints to api.kustom.co. Only generate new credentials if you get authentication errors after switching.

Can I switch environments separately?

Yes. Switch Playground first (if you use it), then Production.

Will shoppers notice the switch?

No.

Can I keep old and new credentials active temporarily?

If you generate new credentials, keep the old ones until your new setup is verified. Do not wait until the deadline.

What happens if I miss the deadline?

API calls to Klarna endpoints will fail after March 31, 2026.

Klarna SSL details

Klarna SSL certificate rotation – April 9, 2026

On April 9, 2026 (10:30–15:00 CEST), Klarna will perform a routine SSL certificate rotation on api.klarna.com and api-na.klarna.com. The new certificate will be issued by DigiCert Global Root G2. See Klarna's maintenance notice for details.

Most merchants are not affected. Standard integrations that do not use certificate pinning will continue to work without any changes.

You may need to act if your systems use certificate authority (CA) pinning or have imported Klarna's certificate chain manually: