SMS Marketing: How Many Characters TeleSign Allows

When planning an SMS campaign, a critical question arises: for sms marketing how many characters telesign and other traditional gateways allow before doubling your costs? Understanding these strict limits is the difference between a highly profitable campaign and a surprise bill that wipes out your margins. In this guide, we will break down exactly how SMS character limits work, how hidden symbols inflate your costs, and how you can bypass these restrictions entirely.

SMS Marketing: How Many Characters TeleSign and Competitors Limit You To

When using traditional cloud communication platforms like TeleSign, Twilio, or Plivo, you are bound by industry-standard telecommunication rules. The absolute standard limit for a single SMS message is 160 characters. However, this limit is highly volatile and depends entirely on the character encoding used. If you exceed this limit by even a single character, your provider will split the message into multiple segments and bill you for each segment individually.

This means if you write a message that is 161 characters, you are not paying for one message; you are paying for two. To make matters worse, when messages are split, some data overhead is required to instruct the recipient's phone on how to reassemble them. This reduces the limit of each split message from 160 characters to 153 characters. Here is how the math works out for standard GSM sms characters:

• 1 Message Segment: 0 to 160 characters
• 2 Message Segments: 161 to 306 characters (153 characters per segment)
• 3 Message Segments: 307 to 459 characters (153 characters per segment)

For small businesses sending operational updates, booking confirmations, or promotional offers, these segments add up fast. If you are using standard APIs, you must closely monitor your maximum characters in texts to avoid budget overruns. If you are tired of dealing with these complex calculations and want a simpler pricing model, you can read our guide on Twilio alternatives for 2026 to see how modern platforms handle this.

The GSM-7 vs. UCS-2 Encoding Split

The reason behind the strict limit on sms characters lies in the encoding standard. By default, networks use GSM-7 encoding, which supports 128 basic characters, including standard Latin letters, numbers, and some common punctuation. Each character in GSM-7 takes up 7 bits of data.

However, if your message contains even a single character that is not part of the GSM-7 alphabet—such as an emoji, a Cyrillic character, an Arabic letter, or even certain stylized punctuation marks—the system must switch to UCS-2 (Unicode) encoding. UCS-2 characters require 16 bits of data each. Consequently, your maximum characters in texts drops instantly from 160 down to 70 characters. If a Unicode message is split, each segment is limited to just 67 characters.

What Special Characters Usually Affect Messages?

Many business owners and developers are shocked when their monthly SMS invoice is double what they budgeted, even though their templates seemed to be under 160 characters. This happens because of hidden Unicode characters that creep into copy-pasted text. So, what special characters usually affect messages the most?

The most common culprit is the smart apostrophe or curly quote (’). If you copy and paste your marketing copy from Microsoft Word, Google Docs, or Apple Notes, those programs automatically convert standard straight apostrophes (') into curly ones (’). When you paste this into an SMS gateway API like TeleSign, the gateway detects a Unicode character. Suddenly, your 150-character message is split into three separate billing segments because the threshold dropped to 70 characters.

If you have ever used an automated gateway, you might have encountered an error message like: message should only contain gsm characters for sms. the following characters are not valid: ’. This warning is designed to protect you from accidental multi-segment charges. Other common characters that trigger this downgrade include:

• Curly quotes (“ and ”)
• Em dashes (—) and en dashes (–)
• Accented characters not in the GSM-7 extension table (like á, í, ó, ú)
• Emojis (😊, 🚀, ⚠️)
• Non-Latin alphabet characters

Do I Need to Convert Simplr Characters in SMS Messages?

A common technical question developers ask is: do i need to convert simplr characters in sms messages? Yes. If you are using traditional APIs, you must implement a sanitization script in your backend. This script should automatically replace curly quotes with straight quotes, em dashes with standard hyphens, and strip out unsupported symbols before hitting the API. Failing to perform this conversion means your gateway will silently upgrade your message to UCS-2, drastically increasing your costs.

How Traditional Gateways Bill You vs. MySMSGate

Traditional gateways like TeleSign, Twilio, and Plivo make a significant portion of their revenue from multi-segment billing. They charge you for every single 160-character (or 70-character) block. If you send a 161-character text, you pay double. If you send a 320-character detailed reminder, you pay triple.

At MySMSGate, we believe this model is outdated and unfair to small businesses. We turn your own Android phone into an SMS gateway. Because the messages are sent directly from your own SIM card using your carrier's plan, we do not have to play by the restrictive segment-billing rules of traditional cloud gateways. We charge a flat fee of $0.02 per SMS sent, regardless of how long the message is. There are no monthly fees, no contracts, and no hidden segment multipliers.

Let's look at a cost comparison for sending 1,000 marketing or operational messages that average 200 characters (which triggers 2 segments under GSM-7 rules):

By leveraging your own Android device, MySMSGate completely bypasses the complex web of carrier registrations and segment fees. This makes it the cheapest SMS API for small business operators who need to send steady, relationship-based notifications to their customer lists without dealing with technical headaches.

Developer Guide: Handling SMS Characters via API

For developers integrating SMS into their application, managing character sets can be a tedious chore. If you are building with TeleSign, you must continuously calculate the max characters to send in a marketing sms before it charges you extra. This involves using library packages to parse the string and determine if it contains Unicode.

With MySMSGate, the integration is incredibly straightforward. You do not need complex sanitization layers to save money. You simply make a single POST request to our API, and we handle the delivery through your connected Android phone. Here is an example of how simple it is to send an SMS using Python:

import requests

url = "https://mysmsgate.net/api/v1/send"
headers = {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
}
payload = {
    "to": "+1234567890",
    "message": "Hello! This is a long marketing message with emojis 🚀 and special characters like ’ that would normally cost you triple on TeleSign. With MySMSGate, it is just one flat rate!",
    "sim_slot": 1
}

response = requests.post(url, json=payload, headers=headers)
print(response.json())

This API call sends the message directly through your Android device's SIM card. The recipient sees your actual phone number, increasing trust and open rates, while you avoid the standard segment billing traps. For more details on setting up this workflow, check out our guide on SMS gateway vs SMS API differences.

Frequently Asked Questions

Here are answers to the most common questions regarding SMS character limits, formatting errors, and gateway pricing.

How to get more characters for a sms on gatekey?

If you are looking at how to get more characters for a sms on gatekey or similar property management platforms, you are usually bound by their built-in gateway integrations. These systems restrict you to 160 characters to keep their own costs down. To bypass these limits, many property managers connect their systems to external APIs like MySMSGate via Zapier or Make.com, allowing them to send unlimited-length messages without character-splitting penalties.

What is the maximum characters per sms in dialog?

The maximum characters per sms in dialog (a major telecom provider in South Asia) follows the global standard: 160 characters for standard GSM-7 text and 70 characters for Unicode (Sinhala, Tamil, or emojis). If you exceed these limits, Dialog will split the message and charge you per segment. Using an Android-based gateway like MySMSGate allows you to send through local Dialog SIM cards while managing the queue via a central web dashboard.

What characters are not allowed in standard GSM-7 SMS?

Standard GSM-7 does not support smart quotes (’, “), emojis, mathematical symbols, or non-Latin alphabets. If your messaging platform throws an error stating 'message should only contain gsm characters for sms. the following characters are not valid', you must replace those characters with standard ASCII equivalents (like replacing ’ with ') to keep your message within the 160-character limit.

Can I send unlimited characters using MySMSGate?

Yes. Because MySMSGate sends messages via your Android phone's native operating system, the OS automatically handles long messages. While long messages are technically split into segments by the cellular carrier, MySMSGate charges you a single flat fee of $0.02 per complete message sent from our dashboard or API, protecting you from multi-segment API billing surprises.