Payment routing optimization is the goal-focused name for payment routing, the entry that explains how transactions are directed between acquirers, processors and networks. Adding "optimization" signals that routing is being tuned deliberately to improve results rather than simply sending every payment down one fixed path.
A merchant with more than one provider can decide, transaction by transaction, where to send each payment. The decision may weigh the cost of each route, the historical approval rate for that card type or country, the speed of settlement and the current health of each provider. A domestic card might go to a local acquirer to benefit from local acquiring, a debit card in the United States might be sent over a cheaper network under least-cost routing, and a payment that receives a soft decline might be retried through another route.
Optimization relies on data and testing. Teams compare routes using approval rates, fraud and chargeback rates, and total fees, then adjust rules or let a model choose. The tools that do this are usually described as smart payment routing and are often part of a payment orchestration platform. Rules on routing choice, such as the US Durbin Amendment's network-choice requirement for debit cards, also shape what is allowed.