Payment instrument priority

Introduction

Payment instruments can be freely reordered by consumers using the wallet dashboard, but the WSP can have a default priority based on the Participating payment system of their choosing. The WSP default priority will be utilized until a consumer creates a custom priority.

This feature allows end-users to define their own ordering while maintaining intelligent category-aware distribution that maximizes conversion rate (success rate) by ensuring the full transaction amount is distributed whenever mathematically possible given available balances and category constraints.

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Currently (for the MVP), the system enforces a fixed priority where vouchers (category-restricted instruments like Monizze FOOD, Pluxee ECO) are always processed before firm funding sources (Bancontact, Xtra).

Distribution Algorithm Goals (in priority order)

1. Comply with end-user's Priority_Order — respect the user-defined sequence of payment instruments
2. Maximize conversion rate (success rate) — intelligently distribute amounts so that full payment succeeds whenever mathematically possible given available balances and category constraints
3. Minimize sub-transactions — reduce the number of individual authorization requests to lower time cost and financial cost per sub-transaction