Deduction Cap

Overview

Deduction cap is a new optional setting on discount rules that lets merchants define a maximum discount amount per currency. When a discount calculation exceeds the cap, the capped amount is applied instead.

Problem

Percentage-based discounts scale linearly with cart value, which can lead to disproportionately large deductions on high-value orders. Merchants had no way to set an upper bound on how much a single discount rule could deduct, making it difficult to run broad percentage promotions while controlling margin impact.

Solution

A discountCap field on all three discount rule types (cart rules, code rules, external rules) that accepts a list of currency-amount pairs. Each entry defines the maximum deduction allowed for that currency.

discountCap: { Caps: [ { units: 50000, currencyCode: "SEK" }, { units: 5000, currencyCode: "EUR" } ] } 

Scope

• Applies to cart rules, discount code rules, and external discount rules

• One cap per currency per rule

• Optional — rules without a cap behave as before

UI

The deduction cap section is located in the General tab of the discount rule form, below the time period limitation. Merchants can add, preview (with formatted currency display), and remove caps per currency. Currency options are derived from configured store markets.