A transaction is cross-border when the buyer and the recipient are in different countries. From the issuing bank's point of view, it arrives flagged as international, and that alone already increases the chance of a decline.

Three things change at once. The cost, because card networks charge an extra fee on cross-border transactions. The approval, because the issuer applies stricter fraud rules. And the experience, because the buyer may see the charge in a foreign currency and still pay IOF or a fee from their own bank.

Processing locally in the buyer's country, when possible, is what removes the international flag and recovers a good part of the lost approval.