March 11, 2021

Terminal Initializations

What is a terminal initialization, and what does it do?

A terminal initialization is a function that sends information about the PINpad terminal to the host processor and, in return, receives additional parameters and information from that host. The information exchanged may vary by region, processing host, and platform and may further differ by device, industry, or business type.

In most cases, the first time a PINpad is connected to a point-of-sale, it must be initialized before it can be used to process transactions. This establishes the relationship in the payment processing environment among device, point-of-sale register terminal, merchant location, and host. Where applicable, it also enrolls and enables the device for encryption.

  • Some of the information that is transmitted or exchanged may include:
  • Host settings—that can be made up of global or individual merchant parameters
  • Exclusion card BIN ranges—that can contain general or individual merchant parameters
  • EMV parameters—for processing contact and contactless chip cards
  • EMV public keys—for all card brands for offline PIN validation and data authentication
  • Encryption keys
  • MAC and PIN keys—for Interac debit processing in Canada

How often is it needed?

Frequency is a tricky question. “Regularly” is recommended, but how that translates for a merchant’s particular solution depends on many factors such as device, merchant profile, capabilities, and host. We recommend that you engage your host processor representative to discuss your specific needs.

How can it be triggered/completed?

The recommended option is to have a user-controlled button to allow for manually-performed initializations. Other standard practices for this process are implementing the initialization to happen when the POS is started, in synch with a user login to the POS, or as a manually-triggered ad hoc option.

In EMV environments, it stands to reason that the PINPad must have the EMV data written before transactions can be processed, so it would make sense to ensure the device is up-to-date for general transaction processing. But there are also situations where that information can be cleared from the PINPad—which may be the case in some PINPad reboots—requiring the initialization/download to take place again, thereby renewing parameters and performing any needed key exchanges for in the environment in question.

Direct Options: MCM

Local Terminal Configuration: Automatic Initialization Flag

PINpads connected to specific versions of MCM can be initialized by enabling the Automatic Initialization Flag in the configuration file. This option does not replace the need for manual or start-up initialization functionality. Its function is to allow the host processor to trigger PINPad initializations based on their responses in the event an initialization or resynchronization needs to happen during the course of daily processing. The feature is not available in all solutions.

Central Server Function: PINPad Initialization

This function resides in the MCM Server and can be accessed by right-clicking on the terminal ID and selecting the Initialize PINPad/Download option appearing in the menu. Each PINpad would need to be initialized separately through this GUI function.

Tender Retail Manager Function: Initialize Terminal

Our estate management application allows for terminals (PINPads) to be initialized individually, at any time, or scheduled in small groupings or across the entire merchant network.


Terminal initialization is a vital function and preventative measure, which, when performed regularly, aids in minimizing interruptions in the client experience and ensures the payment point remains up to date. Talk to our Client Services group for advice on our best practices, or contact your host processor representative for their recommendations.