A communications server apparatus for routing Payment Service Providers (PSP), the communications server comprising a processor and a memory, the communications server apparatus being configured, under control of the processor, to execute instructions stored in the memory, to: determine based on a plurality of pre-determined rules which of a plurality of stored PSPs are applicable for a given transaction; determine the health of the applicable PSPs; and select a PSP for the given transaction based on the health of the applicable PSPs and pre-determined criteria.