Short Message Peer-to-Peer (SMPP)

The SMPP API is available to Advanced Services and SMSCarrier customers. This section contains guidelines for use of our SMPP API, the specifications for the supported versions (v3.3 and v3.4), the PICS document to indicate the level of our support and error codes for delivery outcomes. The official SMS Forum SMPP v5 specification is included here as it clarifies a number of aspects of SMPP as implemented in v3.3 and v3.4 although v5 is not implemented.

The Development Kits section contains a number of SDKs and applications that you can use with our SMPP accounts. We also provide SMSC simulators to aid with testing applications supporting SMPP and further information on this can be found at

SMPP using a TLS connection is supported for those who support such connections in their application and require secure SMPP sessions. Please contact HSL Support for further details on how to use SMPP over TLS.



SMPP v3.3

SMPP v3.4



Delivery Error Codes