The Short Message Peer-to-Peer (SMPP) API is available to Advanced Services and SMSCarrier customers for the delivery of SMS. This section contains guidelines for use of our SMPP API, the specifications for the supported SMPP versions (v3.3 and v3.4), the SMPP PICS document to indicate the level of our support of the SMPP specification and error codes for delivery outcomes. The SMS Forum SMPP v5 specification is included only to clarify aspects of SMPP v3.3 and v3.4. Note that SMPP v5 is not implemented.

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

SMPP API access 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 the SMPP over TLS.