Plain-language definition
A message a subscriber sends to a service, such as a short code for a vote, a query or an opt-in.
Technical definition
P2A traffic is mobile-originated SMS addressed to a short code or long number owned by an application; the SMSC delivers it to the ESME over SMPP deliver_sm or HTTP callback.
Why it matters
P2A enables interactive services and must be routed correctly to the owning application by the SMSC or gateway.
Last reviewed 2026-09-12 by the Guardivia QoS Engineering Team. Product facts on this page describe current capabilities; items marked “where supported”, “optional”, “integration” or “consultancy” are confirmed per deployment.