"Truly unlimited" SMS
doesn't exist.
Carriers' "unlimited" SMS plans are actually throttled by fair use, and pro (A2P) sending is billed per 160-character segment, with carrier fees on top. For truly unlimited sends, at a flat price and with media included: send via WhatsApp through Unlimited Messaging, from your normal account, via REST API.
The context
Is "unlimited" SMS really unlimited?
Consumer "unlimited SMS" remains a person-to-person use governed by fair use, while application-to-number sending (A2P) goes through paid programs like A2P 10DLC in the United States, with carrier fees attached.
On paper, "unlimited SMS" sounds like a simple promise: send as many messages as you want. In reality, carriers' so-called unlimited plans apply to person-to-person use and remain governed by fair-use clauses (reasonable use). Exceed the threshold or send in volume, and the carrier can throttle (slow down), block, or reclassify your traffic. Unlimited is therefore not a guaranteed throughput, but a tolerated average.
As soon as you send from an application - notifications, codes, reminders, marketing - you leave consumer unlimited and enter A2P (application-to-person). There, the rule changes completely: each message is billed, and an SMS is split into 160-character segments (70 in the case of special characters or emojis). A slightly long message means two or three billed segments. In the United States, you also have to register your brand and your campaigns via A2P 10DLC, with carrier fees charged on every send on top of the base price.
In other words, "unlimited" SMS that keeps its promises doesn't exist for professional use. That's exactly the problem Unlimited Messaging solves on another channel: sending via WhatsApp, from your normal account, at a flat price and truly unlimited - media included, with no 160-character segment, no A2P carrier fees, through a simple REST API.
Comparison
Carrier "unlimited" SMS / A2P vs Unlimited Messaging
Same goal - reaching your contacts reliably and with no cap - but two very different models. Here, line by line, is what carrier "unlimited" and A2P hide, and how WhatsApp sending via API frees you from it.
| Carrier "unlimited" SMS / A2Pfair use and per-segment billing | Unlimited Messaging (WhatsApp)your account, via API | |
|---|---|---|
| Truly unlimited? | No: fair use, throttling, and traffic reclassification in volume | Yes: unlimited sends, no hidden cap |
| Billing | Per message, split into 160-character segments (70 with emojis) | Flat subscription, regardless of volume |
| Carrier / A2P fees | A2P 10DLC registration and carrier fees in the United States | No carrier fees or A2P registration |
| Media (image, PDF, video) | Separate MMS, more expensive and unevenly supported | Images, documents, and videos included |
| Read receipts | At best a delivery receipt, rarely a read one | Real-time delivery and read webhooks |
| International | Per-country rate, surcharges, and local A2P compliance | 180+ countries at the same price |
| Setup | Carrier contract or multi-day A2P onboarding | A few minutes, a QR code to scan |
Our approach
True unlimited goes through WhatsApp, from your account
We keep what you expect from a sending channel - reliability, media, receipts, API - and remove what weighs SMS down: no 160-character segment, no A2P fees, no fair-use cap, no business account.
Real unlimited, flat price
A flat monthly subscription, for truly unlimited sends. No per-message billing, no 160-character segment, no surprise when volume rises.
No carrier fees
No A2P 10DLC registration, no carrier fees, no campaign to get approved with carriers. You link your WhatsApp account and you send.
Media included
Images, PDFs, and videos go out in the same message, with no MMS surcharge. Enough to send an invoice, a ticket, or a visual without degrading the experience.
REST API in minutes
A POST to the REST API and the message goes out, with delivery and read webhooks. Python and TypeScript SDKs ready to use to integrate your sends in a few minutes.
- Characters per billed SMS segment (70 with emojis)
- 160Characters per billed SMS segment (70 with emojis)
- A2P carrier fees with Unlimited Messaging
- 0A2P carrier fees with Unlimited Messaging
- Countries covered at the same price
- 180+Countries covered at the same price
- From key to first message sent
- 5 minFrom key to first message sent
How it works
Truly unlimited sends in three steps
- 1
Link your account
Connect your existing WhatsApp account to Unlimited Messaging by scanning a QR code, like WhatsApp Web. No business account, no A2P registration, no dedicated number.
- 2
Generate your API key
Create an API key from your dashboard. It's what authenticates your calls - you have no carrier campaign to get approved beforehand.
- 3
Call the REST API
A POST /messages with the recipient, the text and, if needed, a media file. We route the WhatsApp message and you receive delivery and read webhooks, with no segment or hidden fee.
FAQ
Questions about unlimited SMS
Sources
Sources & references
To check the information in this article for yourself:
Written by
Ilian · Senior Software Engineer
A senior software engineer, he founds and runs several tech companies. He builds products around messaging APIs, automation and AI integration, and shares here what he learns while building.
Truly unlimited sends, starting today.
Link your account, generate your API key, and send your first WhatsApp message in a few minutes - unlimited, media included, with no carrier fees.
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