Interchange

The fee that card schemes route from the acquirer to the issuer for each transaction; it is largely non-negotiable and varies by market and card type.

When this matters

You are decomposing total processing cost into scheme, interchange, and provider margin.
You are modelling the cost impact of method mix or geographic expansion.
You are reviewing pricing proposals from PSPs or acquirers.

Operator tips

Request clear reporting that breaks out interchange vs scheme vs margin.
Be careful when comparing providers; some quote all-in, others separate scheme and interchange.
Use interchange tables for scenario planning, not for exact forecasting of every transaction.

How to use this term

Use this definition when you are aligning stakeholders across product, engineering, finance, and operations. Shared vocabulary makes it much easier to argue about tradeoffs without talking past each other.

For deeper context, pair this term with the free assessment and providers/methods directories. They give you a concrete view of how concepts show up in real stacks.