The checksum is a 256 bit Secure Hash Algorithm (SHA-256) in UTF-8 encoding of the following required fields: accountId + action + customerCountry + orderReference + passphrase. All the fields need to be passed in alphabetical order. This checksum needs to be included within the form as a parameter. 

In case one or more of the following optional fields is used in the form, they should also be included in the checksum calculation:
  • costCenter
  • deliveryMethodsOverrides
  • extraSecure
  • orderWeight
These optional fields need to be inserted into the sequence alphabetically.

For example: if the accountId is 123456, the costCenter is OnlineShop, the customerCountry is BE, the orderReference is 201106161621 and the password is MyPassPhrase, you need to generate the checksum of the following string of the fields concatenated by the ampersand (&):

accountId=123456&action=START&costCenter=OnlineShop&customerCountry=BE&orderReference=201106161621&MyPassPhrase

This string will give you the following checksum hash:
109607d87888155e7d103b8881b5247090dc2090aac65e37b403aa39e1532698

For more information on how to generate SHA256, please refer to your favourite search engine.

REMARK: As shown in the above example, the passphrase is added to the end of the checksum calculation string by placing an ampersand, followed by the passphrase itself. It is not required to put “&passphrase=MyPassPhrase”.