Authorisation
The issuer’s real-time decision to approve a payment and hold the amount against the shopper’s available balance or credit. It is not the money moving — it is the promise that the money is there.
Why it matters to a merchant
The moment everyone at the counter thinks of as "it went through", and it is not yet money. Authorisation checks and reserves; it does not move funds. Almost every argument about "the customer paid but I have not been paid" resolves into the gap between this step and the next two, and understanding that gap is what lets a merchant answer the question instead of escalating it.
Where this comes up
Pages on this site that deal with this in context:
Related terms
In this section: How a payment moves