SMS marketing has one of the best open rates around, but before you dive in it's worth understanding how its cost is measured. The key is the segment: every SMS is counted in segments, and in NotifyBulk that translates into credits —1 credit per segment— included in your plan. Here we explain the model so you can estimate your real usage.
In this guide
The key concept: the SMS segment
It's not counted exactly "per message" but per segment. A standard SMS fits in 160 characters: that's one segment. If your text is longer, it splits into several segments and each counts separately.
| Content type | Characters per segment |
|---|---|
| Plain text (GSM-7) | 160 |
| Plain text, multi-part | 153 per part |
| With emojis or accents (Unicode) | 70 |
| Unicode, multi-part | 67 per part |
That's why a message with one emoji can cost double: that single emoji drops the limit to 70 characters and pushes your text into a second segment —that is, 2 credits instead of 1. Controlling length is the number-one usage lever.
Credits: 1 per segment
In NotifyBulk, the unit of SMS cost is the credit: each segment you send consumes 1 credit from your plan. A 1-segment message uses 1 credit; a 2-segment one, 2 credits. In a campaign, usage is segments × recipients.
| Action | Credits |
|---|---|
| Outbound SMS (from the inbox) | 1 per segment |
| SMS campaign message | 1 per segment × recipients |
| Advanced campaign SMS step | 1 per segment |
| Survey question sent via SMS | 1 per segment |
Your customers' inbound replies do not consume credits. Your balance (used / remaining / plan total) is in Settings → Billing. Credits reset at the start of each period and don't roll over to the next.
Sender registration: the prerequisite people forget
In several markets, before you can send at scale you have to register your sender or brand with the carriers (to fight spam). It's a prerequisite to keep in mind before your first send; a good platform guides you through it.
How to estimate your credit usage
Since each segment is 1 credit, estimating your usage is straightforward:
Example: a 1-segment campaign to 5,000 contacts = 5,000 credits. If those same messages take 2 segments, that's 10,000 credits. That's why checking length before sending can halve your usage. Pick a plan whose credit pool covers your monthly volume.
How to spend fewer credits
- Stay in 1 segment: messages up to 160 characters with no unnecessary emojis = 1 credit per send.
- Segment your list: sending to people who don't convert wastes credits. Send to the right audience.
- Use the right channel: for long or visual messages, email or WhatsApp can perform better. See WhatsApp vs SMS vs Email.
- Centralize everything: with SMS, WhatsApp and email in one panel you compare performance per channel and shift effort to what converts best.
Send SMS, WhatsApp and Email from one place
NotifyBulk gives you SMS, WhatsApp and email in the same panel, with simple monthly plans. Start free.
Start free →Frequently asked questions
How is SMS cost measured?
Per segment. In NotifyBulk each segment consumes 1 credit from your plan; a long SMS splits into several segments and each uses 1 credit. You don't deal with a money price per message: everything is counted in credits.
What is an SMS segment?
A standard SMS fits in 160 characters: that's one segment (1 credit). If your message is longer, it splits into several segments and each counts as 1 credit. Using emojis or special characters lowers the per-segment limit to about 70 characters.
Do my customers' replies consume credits?
No. Only outbound messages consume credits (1 per segment). Your customers' inbound replies don't. Credits reset at the start of each period and don't roll over to the next.
How do I estimate my credit usage?
Multiply the number of messages by the segments in each and by the recipients: that total is the credits you'll consume. Keeping each message in a single segment is the most direct way to spend less. Pick a plan whose credit pool covers that total.
Keep reading: WhatsApp vs SMS vs Email · how much WhatsApp Business API costs.