Klarna Test Cards, Phone Numbers & Sample Data

How Klarna test cards work

Klarna tests run in the playground environment with playground API credentials. When the Klarna widget asks for a card, use 4111 1111 1111 1111 with CVC 123 and expiry 12/28 or any later date. 4687 3888 8888 8881 starts a 3-D Secure flow, and it is also the debit card Klarna says to use for financing tests in the US.

Unlike card gateways, Klarna decides most outcomes from the customer. An email of the form customer+se@klarna.com (with the two-letter code of the market) gets an approved purchase, and adding +denied gets a hard decline. Other suffixes start the new-user sign-up flow or open disputes such as “return” or “goods not received”, so you can test your dispute handling too.

New users go through account creation with a phone number and a one-time code; in the playground any six-digit OTP except 999999 works. Each test account belongs to one market, so you can’t reuse the same email or phone number for Germany and Sweden. The table below lists the approved and denied phone number of every market; Klarna’s sample data also has company data for B2B tests.

Customer emails that approve or deny

Klarna decides most outcomes from the customer, not the card. Replace ** with the two-letter code of the market, for example customer+se@klarna.com for Sweden or customer+de+denied@klarna.com for a denied purchase in Germany.

In the playground any 6-digit OTP except 999999 works. In the US, enter SSN 123456789 when asked. For direct debit in Germany Klarna gives the sample IBAN DE11 5205 1373 5120 7101 31; for bank transfer pick “Demo Bank”. Klarna notes that denied flows can’t be tested in some markets, such as Sweden and Norway.

Klarna test phone numbers and emails by market

Each market has its own approved and denied customer. Use the email and phone number of the same row together; the one-time code is any six digits except 999999, for example 123456.

Filter

Copied from Klarna’s sample customer data. Sweden also needs a sample personal number such as 19770111-6050 for card tests; Norway and Sweden ask for a national identification number before BankID.

Testing Klarna payments step by step

1. Get playground API credentials and point your integration at the playground environment.
2. Start a session for an approved customer such as customer+de@klarna.com and pay with the test card.
3. Repeat with the +denied email to test how your checkout handles a rejected purchase.
4. Use 4687 3888 8888 8881 to test the 3-D Secure step.
5. Test disputes with the +disputed- emails and check your order management flow.

Common errors and fixes

Denied email is approved

Denied flows can’t be tested in some markets, such as Sweden and Norway. Use another market or ask Klarna merchant support.

OTP rejected

Any six-digit code works except 999999.

Account belongs to another country

Test accounts are tied to one market. Use a different email and phone number per country.

Sources

Every value on this page was copied from Klarna’s official documentation, and every card number passes the Luhn check. Checked October 2026; gateways change their test data from time to time, so if a number stops working, check the source:

• Klarna Docs – Sample payment data
• Klarna Docs – Sample customer data