Important information

The API reference is now available here.
The deprecated API reference is available here.


Unzer Installment

Learn more about Unzer Installment and its workflow


If you are using payment type installment-secured, note that this method is now deprecated. It’s currently supported but there are no further developments planned for it.

If you want to access the relevant documentation, see Installment Secured.


Unzer Installment is a part of our Buy Now, Pay Later (BNPL) offering and it’s a very convenient payment option. This payment option offers customers a flexible and secure way to shop online or in-store without having to pay upfront which limits the risks for customers. For merchants the BNPL payment options drive conversion and customer satisfaction. With a strong BNPL partner like Unzer the risks for merchants are equally limited as they are for customers.
The Unzer Installment product is a monthly installment payment method for B2C customers. For merchants, this product guarantees the payout of the full order amount – no matter if the customer pays off the installment or not. That risk is covered by Unzer.

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  • Ease of use: The customer can easily step through the checkout and choose the number of installments in which they want to pay for the goods. They provide their bank account details and the installments will be debited from their account via SEPA direct debit.
  • High level of security: Unzer is addressing the usual danger with installment payments. If the transaction was successful and the shipment transaction has been sent in time, you will receive the funds even if the customer doesn’t send the payment.
  • Preferred payment method for large baskets: The customer can buy higher baskets and pay it in smaller installments over a longer period of time.

Payment workflow

The following diagram explains workflow for Unzer Installment payments.

Unzer Installment workflow

Step 1: Retrieve all available installment plans and let the customers pick one for their purchase

Step 2: Create a paylater-installment payment type resource with the id and the selected months of the step 1 and the IBAN of the customer.

Step 3: Make an authorize call with the paylater-installment resource, the customer resource, and the basket resource.

Step 4: After the transaction, display the result to the customer in the front end of the online shop.

Step 5: When you ship the order, make a charge call to fullfil the payment. Only after this call you’ll get the payout for your transaction.

Integration options

Use pre-built, configurable all-in-one pages with your own mix of payment methods

Use pre-built forms and quickly integrate with minimum work on the client side

Integrate with Unzer using your own payment form