M4 Category Discount or Surcharge

M4 Category Discount or Surcharge is a PrestaShop module that allows store administrators to define custom price adjustments — either discounts or surcharges — for every combination of product category and customer group. This gives merchants fine-grained control over pricing strategies targeted at specific customer segments browsing specific parts of the catalog.

Key features and behaviours of this module:

• Category and customer group matrix: Set individual discount or surcharge values for any pairing of product category and customer group, based on each product's default category and the customer's default group.
• Price chain integration: The module applies its adjustments as a distinct step in PrestaShop's price calculation chain, after built-in catalog prices, quantity discounts, and group reductions have been applied.
• Specific price override: When a discount is set in this module, it takes precedence over any specific price defined for the product — the specific price will be ignored for affected items.

Important compatibility notes: the module is not compatible with PrestaShop's built-in ecotax, should not be combined with other M4 Discount modules simultaneously, and requires that built-in group discounts not be used alongside it to avoid conflicts.

This module is best suited for PrestaShop merchants who need to offer differentiated pricing by both customer segment and product category — for example, applying wholesale discounts to a specific group only within certain categories, or adding surcharges for a particular group purchasing from a given category.