---
title: "Klarna for airlines"
description: "Learn how to accept Klarna payments to airlines."
url: "https://docs.adyen.com/payment-methods/klarna/airlines"
source_url: "https://docs.adyen.com/payment-methods/klarna/airlines.md"
canonical: "https://docs.adyen.com/payment-methods/klarna/airlines"
last_modified: "2025-12-05T13:59:00+01:00"
language: "en"
---

# Klarna for airlines

Learn how to accept Klarna payments to airlines.

[View source](/payment-methods/klarna/airlines.md)

When shoppers select Klarna to make payments to airlines, you have to include specific travel details in `additionalData` and `lineItems` of your [/payments](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments) or [/sessions](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions) request.

## Additional data

Select which endpoint you are using:

### Tab: `/sessions`

To send specific additional data, use:

* The [`additionalData.additionalDataAirline`](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline) object is required and includes:

  | Parameter                                                                                                                                                                                      | Required                                                                                    | Description                                                                                              |
  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- |
  | [airline.customer\_reference\_number](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-customer_reference_number)        | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The alphanumeric customer reference number.                                                              |
  | [airline.leg\[itemNr\].depart\_airport](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-leg-depart_airport)             | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The [IATA](https://www.iata.org/en/services/codes) three-letter airport code of the departure airport.   |
  | [airline.leg\[itemNr\].destination\_code](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-leg-destination_code)         | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The [IATA](https://www.iata.org/en/services/codes) 3-letter airport code of the destination airport.     |
  | [leg\[itemNr\].carrier\_code](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-leg-carrier_code)                         | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The [IATA](https://www.iata.org/en/services/codes) 2-letter accounting code that identifies the carrier. |
  | [leg\[itemNr\].date\_of\_travel](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-leg-date_of_travel)                    | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Date and time of travel in this format: yyyy-MM-dd HH:mm .                                               |
  | [airline.passenger\[itemNr\].first\_name](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-passenger-first_name)         | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | First name of the passenger.                                                                             |
  | [airline.passenger\[itemNr\].last\_name](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-passenger-last_name)           | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Last name of the passenger.                                                                              |
  | [airline.passenger\[itemNr\].traveller\_type](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataAirline-airline-passenger-traveller_type) | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Accepted values: **mr**, **mrs**, or **ms**.                                                             |

  Note: As used in the parameters listed above, `[itemNr]` is a numerical number that has to be included, even if there is only one item (like one passenger), for example **airline.passenger1.first\_name**.

  **Examples:**

  **Example of a single-leg flight for multiple passengers**

  ```json
  {
      "airline.leg1.carrier_code": "W6",
      "airline.leg1.destination_code": "BUD",
      "airline.leg1.depart_airport": "BRI",
      "airline.leg1.date_of_travel": "2024-09-02 15:45",
      "airline.leg1.class_of_travel": "F",
      "airline.passenger1.first_name": "John",
      "airline.passenger1.last_name": "Smith",
      "airline.passenger1.traveller_type": "mr",
      "airline.passenger2.first_name": "Fish",
      "airline.passenger2.last_name": "Bone",
      "airline.passenger2.traveller_type": "mr",
      "airline.customer_reference_number": "OE2WYY"
  }
  ```

  **Example of a multi-leg flight for multiple passenger**

  ```json
  {
      "airline.leg1.carrier_code": "W6",
      "airline.leg1.destination_code": "BUD",
      "airline.leg1.depart_airport": "BRI",
      "airline.leg1.date_of_travel": "2024-09-02 15:45",
      "airline.leg2.carrier_code": "EA",
      "airline.leg2.destination_code": "CUD",
      "airline.leg2.depart_airport": "ABC",
      "airline.leg2.date_of_travel": "2024-10-02 15:45",
      "airline.passenger1.first_name": "John",
      "airline.passenger1.last_name": "Smith",
      "airline.passenger1.traveller_type": "mr",
      "airline.passenger2.first_name": "Fish",
      "airline.passenger2.last_name": "Bone",
      "airline.passenger2.traveller_type": "mr",
      "airline.customer_reference_number": "OE2WYY"
  }
  ```

* In addition, the [`additionalData.openinvoicedata.merchantData`](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-additionalData-AdditionalDataOpenInvoice-openinvoicedata-merchantData) parameter may be provided:

  Include all relevant details, like product, purchase, and customer details, in a Base64 encoded JSON object that comply with [Klarna's specification](https://docs.klarna.com/api/extra-merchant-data/).

  If the `merchantData` does not meet the format in the Klarna specification, the data will not be consumed by Klarna's risk engine. There will also not be any validation errors from Klarna in this case, so take care to send the correct details in the correct format.

### Tab: `/payments`

To send specific additional data, use:

* The [`additionalData.additionalDataAirline`](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline) object is required and includes:

  | Parameter                                                                                                                                                                                      | Required                                                                                    | Description                                                                                              |
  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- |
  | [airline.customer\_reference\_number](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-customer_reference_number)        | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The alphanumeric customer reference number.                                                              |
  | [leg\[itemNr\].depart\_airport](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-leg-depart_airport)                     | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The [IATA](https://www.iata.org/en/services/codes) three-letter airport code of the departure airport.   |
  | [leg\[itemNr\].destination\_code](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-leg-destination_code)                 | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The [IATA](https://www.iata.org/en/services/codes) 3-letter airport code of the destination airport.     |
  | [leg\[itemNr\].carrier\_code](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-leg-carrier_code)                         | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | The [IATA](https://www.iata.org/en/services/codes) 2-letter accounting code that identifies the carrier. |
  | [leg\[itemNr\].date\_of\_travel](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-leg-date_of_travel)                    | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Date and time of travel in this format: yyyy-MM-dd HH:mm .                                               |
  | [airline.passenger\[itemNr\].first\_name](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-passenger-first_name)         | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | First name of the passenger.                                                                             |
  | [airline.passenger\[itemNr\].last\_name](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-passenger-last_name)           | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Last name of the passenger.                                                                              |
  | [airline.passenger\[itemNr\].traveller\_type](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataAirline-airline-passenger-traveller_type) | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Accepted values: **mr**, **mrs**, or **ms**.                                                             |

  Note: As used in the parameters listed above, `[itemNr]` is a numerical number that has to be included, even if there is only one item (like one passenger), for example **airline.passenger1.first\_name**.

  **Examples:**

  **Example of a single-leg flight for multiple passengers**

  ```json
  {
      "airline.leg1.carrier_code": "W6",
      "airline.leg1.destination_code": "BUD",
      "airline.leg1.depart_airport": "BRI",
      "airline.leg1.date_of_travel": "2024-09-02 15:45",
      "airline.leg1.class_of_travel": "F",
      "airline.passenger1.first_name": "John",
      "airline.passenger1.last_name": "Smith",
      "airline.passenger1.traveller_type": "mr",
      "airline.passenger2.first_name": "Fish",
      "airline.passenger2.last_name": "Bone",
      "airline.passenger2.traveller_type": "mr",
      "airline.customer_reference_number": "OE2WYY"
  }
  ```

  **Example of a multi-leg flight for multiple passenger**

  ```json
  {
      "airline.leg1.carrier_code": "W6",
      "airline.leg1.destination_code": "BUD",
      "airline.leg1.depart_airport": "BRI",
      "airline.leg1.date_of_travel": "2024-09-02 15:45",
      "airline.leg2.carrier_code": "EA",
      "airline.leg2.destination_code": "CUD",
      "airline.leg2.depart_airport": "ABC",
      "airline.leg2.date_of_travel": "2024-10-02 15:45",
      "airline.passenger1.first_name": "John",
      "airline.passenger1.last_name": "Smith",
      "airline.passenger1.traveller_type": "mr",
      "airline.passenger2.first_name": "Fish",
      "airline.passenger2.last_name": "Bone",
      "airline.passenger2.traveller_type": "mr",
      "airline.customer_reference_number": "OE2WYY"
  }
  ```

- In addition, the [`additionalData.openinvoicedata.merchantData`](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-additionalData-AdditionalDataOpenInvoice-openinvoicedata-merchantData) parameter may be provided:

  Include all relevant details, like product, purchase, and customer details, in a Base64 encoded JSON object that comply with [Klarna's specification](https://docs.klarna.com/api/extra-merchant-data/).

  If the `merchantData` does not meet the format in the Klarna specification, the data will not be consumed by Klarna's risk engine. There will also not be any validation errors from Klarna in this case, so take care to send the correct details in the correct format.

## Line items

Select which endpoint you are using:

### Tab: `/sessions`

For airline payments, the mandatory parameters that must be included in the [lineItems](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-lineItems) object, include:

| Parameter                                                                                                                              | Required                                                                                    | Description                                      |
| -------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | ------------------------------------------------ |
| [lineItems.quantity](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-lineItems-quantity)                     | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Number of items.                                 |
| [lineItems.description](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-lineItems-description)               | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Description of the line item. Max length: 10000. |
| [lineItems.amountIncludingTax](https://docs.adyen.com/api-explorer/Checkout/latest/post/sessions#request-lineItems-amountIncludingTax) | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Item amount including the tax, in minor units.   |

### Tab: `/payments`

For airline payments, the mandatory parameters that must be included in the [lineItems](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-lineItems) object, include:

| Parameter                                                                                                                              | Required                                                                                    | Description                                      |
| -------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------- | ------------------------------------------------ |
| [lineItems.quantity](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-lineItems-quantity)                     | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Number of items.                                 |
| [lineItems.description](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-lineItems-description)               | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Description of the line item. Max length: 10000. |
| [lineItems.amountIncludingTax](https://docs.adyen.com/api-explorer/Checkout/latest/post/payments#request-lineItems-amountIncludingTax) | ![-white\_check\_mark-](/user/data/smileys/emoji/white_check_mark.png "-white_check_mark-") | Item amount including the tax, in minor units.   |

## Capture payments

Because flight bookings are locked when the payment is made, immediate capture (also referred to as auto-capture) is supported by Klarna. However, the default manual capture flow is also supported.
