High-throughput SMS across 200+ countries — millisecond OTPs and million-scale campaigns on the same gateway. Direct operator routes, provider failover, and real-time DLRs on every message.
The flow
01 · SUBMIT
Message accepted via SMPP bind or REST, validated and queued in milliseconds.
02 · FILTER
Spam, opt-out, and sender-ID checks; per-destination rating applied.
03 · ROUTE
Best direct operator route selected, with automatic failover to backups.
04 · DELIVER
Handed to the operator SMSC and delivered to the handset.
05 · DLR
Real-time delivery receipt streamed back via webhook or SMPP.

Delivery intelligence
Track delivery rates per route, country, and operator in real time. Spot a failing route before it costs you conversions, and switch traffic with one click.
Capabilities
NU SMS runs a hardened SMPP messaging core — extended with our own routing engine, campaign tooling, and operator console, so you get carrier-grade throughput and a modern API without managing a single bind yourself.
Features
Built for the demands of modern telecoms and digital infrastructure — reliable, programmable, and production-ready.
Send millions simultaneously; auto-respond to inbound keywords and run conversational flows.
Delivery receipt webhooks per message — know instantly if an SMS delivered, bounced, or buffered.
Direct operator connections in 200+ countries — tier-1 access only, no grey routes.
Native SMPP for high-throughput telco integration, plus a clean REST API for modern stacks.
Send in code
Fire a single OTP or a bulk batch with the same endpoint. Idempotent, versioned, with DLR webhooks out of the box.
# send a transactional OTP
curl -X POST https://api.nusms.co/v1/messages \
-H "Authorization: Bearer $NU_SMS_KEY" \
-d '{ "to": "+27825550142", "from": "NUSMS",
"text": "Your code is 4821", "dlr": true }'
# → 202 Accepted
{ "id": "msg_7Kd1…", "status": "queued",
"parts": 1, "route": "mtn-za-direct" }Free test credits, no commitment, and a 30-day pilot to prove delivery rates on your traffic.
No credit card required · Free test credits · Cancel anytime