BulkSMS provides a number of APIs to allow developers to integrate functionality into their systems.
Our REST API uses JSON for requests and responses. This is the API we recommend for all new integration work.
Our HTTP API is based on form encoded requests and text responses.
SMPP is a standard within the mobile industry.
If you’re integrating an existing application which has support for SMPP and you are expecting to send high volumes, this may be a good choice.