# What is an SMS API?

> An SMS API is a REST or SMPP endpoint that enterprise applications call to send SMS messages programmatically. It abstracts the SMSC, the operator connections, the SS7 signalling, and the regulatory compliance — exposing a simple POST /messages or SMPP submit_sm command.

- Canonical URL: https://www.broadnet.me/answers/what-is-sms-api
- Language: en
- Last reviewed: 2026-09-30
- Publisher: BroadNet (https://www.broadnet.me)

## REST vs SMPP

REST (HTTPS POST) has no fixed per-account rate limit at BroadNet — throughput is sized to your traffic. SMPP 3.4 binding suits sustained volumes of several hundred messages per second or workloads that need persistent binds (capacity per bind agreed with your account team, up to 30,000 SMS/s per node) — typically OTP services, large e-commerce, or operator-level traffic.

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [How do you send an SMS via API?](https://www.broadnet.me/answers/how-to-send-sms-via-api)
- [SMPP 3.4 vs SMPP 5.0 — what changed and what to use](https://www.broadnet.me/answers/smpp-3-4-vs-5-0)
- [What is SMPP?](https://www.broadnet.me/answers/what-is-smpp)
- [SMS API](https://www.broadnet.me/products/sms-api)
- [Developer docs](https://www.broadnet.me/developers)