Plain-language definition
A device holding many SIM cards used to terminate commercial traffic as if it were local subscribers.
Technical definition
SIM boxes present A2P messages (or calls) as MO traffic from local MSISDNs; they are detected by MSISDN behavioural profiling, velocity and content analysis, and confirmed by handset evidence showing local numbers instead of the submitted sender.
Why it matters
SIM boxes bypass interconnect charges and hide the true originator.
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.