We shipped explicit Wallet Conversion Rate controls in Flexprice to answer that cleanly.

Each wallet can now define: • conversion_rate — how credits map to currency when spending • topup_conversion_rate — optional rate used only when adding credits

This supports use cases like promotional top-ups, bonus credits, or discounted purchases while keeping invoice calculations consistent.

Wallets store credits.Invoices remain in a single base currency. Conversion defines the relationship between the two.

The goal is simple: make credit systems flexible for product teams and predictable for finance teams. Happy to answer questions about edge cases or implementation details.