Bulk SMS from R0.16, anywhere you send it
Campaigns, one-time passwords and transactional alerts to virtually any network on earth, over a REST API or an SMPP bind. Real delivery receipts from the operator, per-network reporting, and throughput controls that keep a 200 000-message send from taking your own systems down with it.
Zephyr Bulk SMS at a glance
- Global A2P coverage with direct interconnects in the markets we serve deepest
- From R0.16 per SMS to South African networks, dropping with volume
- Billed in your currency — ZAR, USD, EUR or GBP
- REST API or SMPP bind — pick the integration that matches your volume
- Honest character counting — GSM-7 extended characters billed as two septets, as the standard requires
- Two-way messaging with replies delivered to your webhook in real time
- Compliance per market — sender-ID registration, 10DLC, WASPA, opt-out enforcement in the send path
SMS still lands where other channels don't
Across most of the world SMS still reaches a phone that has signal and nothing else — no app, no data bundle, no account. In emerging markets that gap is the whole story; in mature ones SMS remains the highest-open-rate channel there is.
One-time passwords
Login and transaction verification where latency matters. Priority routing so an OTP doesn't sit behind a marketing campaign.
Transactional alerts
Statements, payment confirmations, delivery updates and appointment reminders triggered from your own systems over the API.
Campaigns
Scheduled bulk sends with list management, personalisation, throughput pacing and per-network delivery breakdown.
Two-way conversations
Confirmations, surveys and support over SMS-enabled numbers, with replies routed straight into your application.
One POST to send. One webhook to know it arrived.
The REST API covers most business applications. When you outgrow HTTP — or you're an aggregator reselling capacity — bind over SMPP for sustained throughput and finer control over message parts and receipts.
- REST API over HTTPS with API-key auth, for application integration
- SMPP 3.4 bind for high-volume senders and aggregators
- Delivery receipts correlated back to your original message ID
- Webhooks for inbound messages and status changes
- Sandbox for testing before you spend anything
# Send a single message curl -X POST https://api.zephyrtelecomms.com/v1/sms \ -H "Authorization: Bearer $ZEPHYR_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "to": "+27821234567", "from": "YourBrand", "text": "Your OTP is 481920. Valid 5 minutes.", "reference": "otp-8f21c4" }' # Response { "id": "msg_01JBQK7X9", "status": "submitted", "parts": 1, "encoding": "GSM7", "cost": "0.1400", "currency": "ZAR" }
How your message length is actually counted
Character counting determines what you pay. Providers that round it in their own favour cost you money on every send. Here is exactly how we count.
| Encoding | Single message | Per part when concatenated | When it applies |
|---|---|---|---|
| GSM-7 | 160 characters | 153 characters | Standard Latin text, digits and common punctuation |
| GSM-7 extended | 2 septets each | 2 septets each | € { } [ ] ~ | ^ and the form feed character |
| UCS-2 | 70 characters | 67 characters | Any character outside GSM-7 — accents, emoji, non-Latin script |
Two things catch people out. First, a single emoji anywhere in the message switches the whole message to UCS-2 and cuts your limit from 160 to 70. Second, the eight extended GSM-7 characters each consume two septets — a message with four euro signs is four characters longer than it looks. Our API returns the encoding and part count in the send response, so you can see the cost before the message leaves.
Every market has its own rules. We apply them before submission.
A2P messaging is regulated differently in every market — WASPA in South Africa, 10DLC registration in the United States, sender-ID pre-registration across much of Europe, the Middle East and Asia. Enforcement after the fact is too late; the rules have to run before the message is submitted.
Opt-in recorded
Consent state stored per recipient with a timestamp and source, so you can evidence lawful basis if challenged.
Enforced before send
Opt-out replies processed automatically and suppression applied at submission — not cleaned up afterwards.
Registered sender IDs
Alphanumeric sender IDs registered per market before use, so traffic is identifiable where the regulator requires it.
Cost ceilings
Per-unit cost ceilings and blocked-prefix rules stop a mis-keyed list from sending premium traffic by accident.
Bulk SMS questions
How do I send bulk SMS?
You need four things: a provider with routes into your destination networks; a registered sender ID or SMS-enabled number valid in that market; a recipient list where every contact has opted in; and content meeting the local regulatory code. With Zephyr you upload or API-post the list, choose the sender, and the platform handles throughput pacing, delivery receipts and opt-out processing.
What does bulk SMS cost?
Per message, with volume tiers reducing the unit rate as monthly volume rises. Cost varies substantially by destination country, network and route quality — a message to a South African mobile and one to a UAE mobile are not comparable. We quote against your actual destination mix rather than publishing a headline rate that doesn't survive contact with real traffic.
How many characters is one SMS?
A single GSM-7 encoded SMS holds 160 characters; concatenated parts hold 153 each because every part carries a header. Eight extended characters — € { } [ ] ~ | ^ — consume two septets each. Any character outside GSM-7 switches the whole message to UCS-2, dropping the limit to 70, or 67 per part.
What is the difference between an SMS API and SMPP?
A REST SMS API sends over HTTPS and suits application integration at moderate volume. SMPP is the protocol carriers use between each other — a persistent binary session with far higher sustained throughput and finer control over receipts and message parts. High-volume senders and aggregators bind over SMPP; most business applications use REST.
What is WASPA and does it apply to me?
WASPA is the Wireless Application Service Providers Association of South Africa. Its code of conduct governs commercial messaging to South African subscribers — consent, opt-out handling, sender identification and content standards. If you send commercial SMS to South African numbers, it applies to your traffic regardless of where your business is based.
Do you support two-way SMS?
Yes. Replies to SMS-enabled numbers are delivered to your webhook or SMPP bind in real time, so you can run conversational flows, confirmations and opt-out handling programmatically.
Can I resell SMS capacity to my own customers?
Yes. Aggregators and resellers bind over SMPP and layer their own markup using the platform's multi-tier reseller structure. See wholesale SMS routes.
Test it in the sandbox before you spend
Create an account for free sandbox access. Send test traffic, check delivery receipts and see exactly how messages are counted and costed.