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Before a merchant can accept DCC transactions, you need to register them in Fexco’s Mercury platform, a central system for managing merchant configurations, transaction processing, and reporting. You assign each merchant a configuration that defines their currencies, commission splits, and rate behavior. This process is called merchant boarding. This page explains why boarding is required, how templates and identifiers work, and what the boarding lifecycle looks like.

Purpose of merchant boarding

The rate service will not return a DCC offer for a merchant that has not been boarded into Fexco. When a cardholder presents a foreign card, the rate service looks up the merchant’s ID against the list of boarded merchants. If the merchant is not recognized, the request is rejected and no currency conversion is offered. Boarding also determines what the rate service returns. The configuration assigned during boarding controls which currencies are eligible for conversion, what commission splits apply, and whether DCC, MCP, or both are active for that merchant. The following diagram shows how a boarding request reaches the rate service.

Boarding methods

You can board merchants through the Boarding API or Boarding File Upload (XML). Both methods register merchants in the same system, but they differ in format, automation level, and which lifecycle operations they support. See Choose a boarding method for a detailed comparison.

Key identifiers

Merchant boarding involves several identifiers, but two are essential across the entire DCC system. Fexco assigns both during your onboarding setup, and you use them in every boarding request, rate service call, and transaction import file:
  • Acquirer ID: a three-letter code that identifies your organization.
  • Card Acceptor ID (MID): a 4–16 character alphanumeric identifier for a specific merchant. You provide this value when you board the merchant.
The Card Acceptor ID has different field names across DCC APIs and file formats. See Field name mapping for the complete cross-reference.

Templates

A template is a pre-configured set of rules that Fexco creates for your acquirer during onboarding setup. When you board a merchant, you assign them to a template, and that template determines how the rate service behaves for that merchant. A template controls:
  • Allowed currencies: which foreign currencies the rate service will return offers for.
  • Pricing currency: the currency the merchant prices transactions in (for example, GBP or EUR).
  • Commission splits: how the margin is divided between all parties (for example, the acquirer, PSP, merchant, and Fexco).
  • Rates activation: whether DCC rates, MCP rates, or both are active for merchants on this template.
You do not create or modify templates yourself. Fexco provides the template identifier during your onboarding setup, and your role is to assign the correct template to each merchant. How you reference the template depends on the method you use. See Choose a boarding method for a comparison.

Boarding lifecycle

When you board a merchant, you link their Card Acceptor ID to a template by submitting a boarding request through the Boarding API or XML. The rate service then uses that template’s configuration to return DCC offers for that merchant. Every boarded merchant follows a defined lifecycle:
  1. Create a merchant: You register a new merchant and assign them to a template. Once boarding completes successfully, the merchant becomes active and eligible for DCC rate offers. All three boarding methods support creation.
  2. Update a merchant (optional): You update a boarded merchant’s configuration, such as switching templates or modifying allowed currencies. Only Boarding File Upload (XML) supports updates.
  3. Deactivate a merchant (optional): When you need to remove a merchant from active DCC participation, you deactivate them. After deactivation, the rate service stops returning offers for that merchant. The Boarding API and Boarding File Upload (XML) support deactivation.
  4. Reactivate a merchant (via Fexco): If you need to restore a deactivated merchant to active status, contact your Fexco project manager. Reactivation is not self-service.
The following diagram shows the same lifecycle at a glance, including which boarding methods support each step.

Next steps

Now that you understand how merchant boarding works, choose your boarding method and start integrating: