MasterCard Terminal ID Handling

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MasterCard Register Number Policy & Requirements:

  • The MasterCard Register number is implemented to provide the card brand with more detail in the event of card fraud at a physical location.
  • This number will allow the investigation of fraud to be linked to a specific lane at a specific merchant location, giving more valuable information to the card brand when investigating. 
  • This number must be unique for each register at a single location. 
  • The number itself is sent over by the POS within the Transport Create Transaction request as the Terminal ID. 

The Terminal ID Field that is submitted in a Transport Create Transaction API request is used to fulfill the MasterCard Register Number requirement. Although this is a MasterCard requirement, each processor has a different format or standard for how they require this field to be sent in. We are adding the handling of this field into our available processors and products. This field is currently only supported in Cayan Genius. Support for Cayan's other product lines, including Transport and MerchantWARE, will be available in a future version of those products. 

Proper Handling of Cayan Terminal ID Field: 

The implementation of the Terminal ID field within the POS should be flexible. There are a few requirements that it should meet in order to enable the use of any processor.
  • The POS must make the field which populates the Terminal ID value a configurable field. If this is hard coded to a set of values there can be issues using multiple processors. 
  • The field for Terminal ID must be able to accept between 1-16 characters.
  • The field for Terminal ID must only be able to accept numeric values. 

Summary: The addition of the Terminal ID field is fairly simple, but it is important to handle the values submitted with care. Ensuring that the field is configurable will prevent restrictions related to which platform a customer can be configured for. 

Support: For additional questions on how to handle the use of the Terminal ID field for the MasterCard Register Number requirements please contact Certification Engineering at

Resources: Processor & Product Support Matrix 

Value Required
Vantiv IBM 2 digits exactly 01
Elavon 8 digits exactly 01234567
Rapid Connect 8 digits 01234567