Long SMS API —
write the whole message
SMS splits anything longer than 160 characters into segments, and everyone who resells SMS bills each segment separately. Here segments are a technical detail, not a billing unit: our app on your Android phone sends messages up to 7 segments (~1071 characters Latin, ~469 Cyrillic) through your own SIM. Recipients see one message — and they can reply to it.
Why segments exist at all
The 160-character rule
The GSM standard caps a single SMS at 160 chars (GSM-7), or 70 in UCS-2 — the encoding Cyrillic, Arabic, Chinese and emoji require. Longer texts are carried as segments of 153 (or 67) characters each.
Phones reassemble them
Modern handsets stitch the segments back into one bubble. The recipient sees a single message, scrolls it, replies to it — the split is invisible on their side.
Resellers count them
Providers that buy carrier traffic pay for every segment and pass that on with markup. A 600-character reminder is billed four times — in every country, on every invoice.
Your own SIM mostly doesn't
On the unlimited-text plans that are standard in much of the world, extra segments cost the sender nothing at all. On bundle plans they draw a few units from a pack. Either way — nothing like a multiplied invoice.
Where long messages earn their keep
Appointment reminders
«Your appointment with Dr. Smith on Tuesday March 15 at 3pm. Address: 123 Main St. Reply CONFIRM or call 555-1234.» — 200+ chars, two segments at a per-segment provider. Here: no difference.
Order and delivery updates
«Hi {name}, your order #{{order}} (3 items, $42) shipped via {carrier}. Tracking: {url}. Expected delivery: {date}.» — easily 300+ chars on real data.
OTP with branding
«Your {brand} verification code is 123456. Don't share this code. {brand} will never ask for it. Code valid for 5 min.» — looks short, runs three segments at per-segment providers.
Non-Latin scripts
Cyrillic, Arabic, Chinese and emoji use UCS-2: 70 chars per segment instead of 160. A 180-character message in those scripts is already three segments — here the script your customers read never changes what you pay.
Customer-service replies
«Hi, sorry about the delay — your refund has been processed and will appear in 3-5 business days. Reference: ABC-123. Anything else?» Natural, human replies run 200+ chars without trying.
Event confirmations
«You're confirmed for {event} on {date} at {venue} ({address}). Doors open 19:00. Bring ID. Add to calendar: {url}.» — six variables, naturally long.
How it works
Install the app
From Google Play, on any Android phone with a working SIM. A spare handset plugged in at the office is the usual setup.
Pair by QR code
Scan the code from your dashboard — the phone is linked to your account, and that is the entire setup.
Send the full text
POST the whole message to /api/v1/send — the phone handles the multipart mechanics, and delivery status comes back.
What length costs — here and elsewhere
A per-segment bill multiplies the destination price. At published per-message rates of $0.008 to $0.39 (checked August 2026), a four-segment message costs anywhere from about $0.03 to $1.56 — per recipient, per send. Write naturally for a month and the multiplication is most of the invoice.
On your own SIM, the same message rides your ordinary mobile plan. As of August 2026, unlimited texting is the standard plan in 12 countries — including the US, the UK and Germany — where extra segments cost nothing at all. In bundle markets they draw from packs that cost almost nothing: in Tanzania, 10,000 SMS go for about $0.57.
And our subscription doesn't count messages, let alone segments. $10.00/month per phone, $5.00/month for each additional one. A 100-character confirmation and a 1071-character update cost exactly the same: nothing on top of the subscription.
Carrier tariffs and per-message rates above were checked in August 2026. Plans and prices change — verify before relying on them.
≤ 70 chars (Cyrillic)
(short notification)
(appointment reminder)
(rich notification + CTA)
(maximum)
Honest about the limits
The 7-segment cap protects your SIM, not our revenue. Carriers flag phones that blast out very long marketing messages; a blocked number breaks your whole stack. Past ~1071 characters the API returns 413 with the actual segment count so your code can split cleanly. Length never touches the bill either way.
The phone itself is a consumer device on a consumer plan. The US industry code (CTIA, 2023) describes a typical subscriber as sending at most 1,000 messages a day at 15–60 per minute, with no more than 25 near-identical repeats of one text; Indian plans cap texting at 100 a day. The honest zone is hundreds of varied messages a day to your own customers — and for the US, note that CTIA treats business traffic as A2P regardless of volume.
If you send a few short OTPs a month, per-message billing can be cheaper; if you need millions of messages with guaranteed throughput and a registered brand sender, carrier platforms are the right tool. The middle — real sentences to your own customers, every day — is where this product lives.
FAQ
Why do SMS APIs charge several times for one message?
The SMS protocol caps a single message at 160 GSM-7 characters, or 70 for Cyrillic, Arabic, Chinese and emoji. Anything longer travels as segments of 153 (or 67) characters, and carriers count each segment separately. Providers that resell carrier traffic inherit that per-segment cost and pass it on: a 200-character notification is billed twice, a 600-character reminder four times. It is not a trick — it is their cost structure. Ours is different: we buy no traffic, so there is nothing to count.
What is the maximum message length?
Up to 7 segments per send — roughly 1071 characters in GSM-7 (Latin) or 469 in UCS-2 (Cyrillic, Arabic, Chinese, emoji). Beyond that the API returns 413 with the actual segment count so your code can split cleanly. The cap protects your SIM, not our revenue: carriers flag phones that blast out very long marketing messages, and a blocked number breaks everything. Length never affects the bill.
Does a long message arrive as one SMS or several?
As one. Modern phones reassemble multipart SMS automatically — the recipient sees a single bubble and replies to it like any other text. On the network it still travels as separate segments, which matters only for your own plan's counting — and on the unlimited-text plans that are standard in much of the world, not even for that.
What does a long message actually cost me?
On our side, nothing beyond the subscription: $10.00/month per phone, with messages and segments uncounted. On the carrier side, whatever your plan says about SMS. As of August 2026, unlimited texting is the standard plan in 12 countries including the US, the UK and Germany, so extra segments cost nothing at all; in bundle markets they draw a few units from packs that cost very little — in Tanzania, 10,000 SMS cost about $0.57. At per-message APIs the same message multiplies a $0.008 to $0.39 destination rate by every segment.
When is per-segment billing actually the better deal?
When you send very little, very short, or very much. A few short OTPs a month can be cheaper on per-message billing than on any subscription. Millions of messages a month with guaranteed throughput and a registered brand sender is carrier-platform territory, and we will not pretend otherwise. The middle — a business writing full sentences to its own customers every day — is where per-segment billing hurts and where this product lives.
Can I see the segment count before sending?
Yes. The web send page counts segments live as you type, the API returns the count with the message, and a 413 response for an over-long message includes both the actual count and the cap so your code can split programmatically. The count matters for the cap and your SIM's health — never for billing.
Write the whole message. The bill doesn't care.
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