Short Message Service (SMS) remains one of the most efficient ways to send messages, but it comes with a key restriction: the maximum number of characters allowed per text. Whether you're crafting marketing messages, customer notifications, or personal texts, understanding these limits helps ensure clear, cost-effective, and compliant communication.
A standard SMS allows for 160 characters, but if the message contains special symbols or emojis, the limit drops to just 70 characters due to a different encoding system. If a message exceeds these limits, it turns into a multi-part message, which can increase costs and impact readability.
For businesses, staying within the limit isn’t just about efficiency—it also helps with SMS compliance and cost control. In this guide, we’ll break down SMS character limits, explain what happens when you exceed them, and explore why certain characters reduce your available space.
Understanding SMS character limits
SMS messages rely on specific encoding systems that determine how many characters fit in a single message. The two main types—GSM-7 and UCS-2—affect message length and whether a message is classified as a Unicode message. Understanding these differences is key to optimizing your text messages.
The character limit in a standard SMS depends on the encoding used. Most messages use GSM-7 encoding, which supports 160 characters and includes basic Latin letters, numbers, and common symbols. However, if a message contains special symbols, emojis, or non-Latin scripts, it switches to UCS-2 encoding, reducing the limit to 70 characters per message.
Standard SMS: 160 Characters
- Uses GSM-7 encoding, the default for most SMS messages
- Supports Latin letters, numbers, and common punctuation
- Allows for longer messages before triggering a multi-part message
Unicode Messages: 70 Characters
- Uses UCS-2 encoding when the message contains Unicode characters (e.g., emojis, accented letters, or symbols)
- Reduces the maximum number of characters per message
- Can increase SMS costs due to segmentation into a multi-part message
What happens when you exceed the limit?
If your SMS message exceeds the limit, it is automatically split into multiple parts. This process, known as concatenated SMS, ensures that recipients see the message as a single text rather than multiple separate messages. However, there are some downsides:
- Each segment includes metadata, reducing the available character count per message to 153 characters instead of 160.
- More segments mean higher costs, as each additional part is billed separately.
- SMS compliance is crucial; businesses must be mindful of messaging regulations and avoid excessive segmentation to prevent unnecessary charges.
For example, a 320-character message will be broken into three separate parts, each containing 153 characters instead of 160. This results in additional costs and potential readability issues if the messages arrive out of order.
Why do special characters reduce the limit?
When a message contains special characters—such as emojis, accented letters, or unique symbols—it triggers UCS-2 encoding, which reduces the character limit from 160 to 70 characters per message.
What Triggers Unicode Messages?
- Emojis
- Non-Latin scripts (e.g., Arabic, Chinese, Cyrillic)
- Unicode characters like €, →, “ ”
Since Unicode encoding requires more data to use these characters, they take up more space, leading to fewer available characters per message. Businesses and individuals should be mindful of this when composing texts to avoid unnecessary segmentation and extra charges.
Strategies for writing effective SMS messages
Crafting effective SMS messages requires balancing brevity with clarity. Since SMS has a maximum number of characters, every word should serve a purpose. Whether you're engaging customers through SMS marketing, sending notifications, or promoting offers, strategic writing ensures your message is impactful and easy to understand. Below are key strategies to help you optimize your SMS communication.
Be clear and concise
SMS messages should get straight to the point. Avoid unnecessary words or filler text—your audience should understand the message instantly. Instead of “We are pleased to inform you that your order has been shipped,” say “Your order has shipped! Track it here: [link].”
Use abbreviations and shortcuts wisely
Common abbreviations like "appt" (appointment) or "b4" (before) help save space, but overusing them can make messages confusing. When clarity is more important than brevity, especially in SMS marketing or customer service, spell out key details. Additionally, SMS short codes (e.g., "Text JOIN to 12345") can streamline customer engagement while keeping messages concise.
Remove unnecessary punctuation and formatting
Excessive punctuation or special formatting (e.g., multiple exclamation marks, ellipses, or unnecessary capitalization) wastes character space. A clean, professional SMS reads better and stays within the limit without affecting readability.
Prioritize important information
People often skim messages, so put the most important details first. In SMS marketing, this means highlighting discounts, deadlines, or action steps upfront. Instead of:
"Hi! We’re excited to share that we have a 20% discount on all shoes this weekend. Visit us at [link]."
Say:
"20% off all shoes this weekend! Shop now: [link]."
Utilize links for extended information
If you need to share detailed information, include a link rather than sending a lengthy message. A short SMS with a CTA (call to action) keeps engagement high while directing recipients to full details on your website or landing page.
While emojis can enhance branding, they trigger UCS-2 encoding, cutting the maximum characters per message from 160 to 70. If branding requires emojis, use them sparingly and test messages before sending to ensure readability and cost-effectiveness.
Consider SMS templates for efficiency
Using SMS templates can streamline messaging, especially for SMS sales campaigns, appointment reminders, or customer support. Prewritten templates help maintain consistency while allowing personalization where needed.
Alternative solutions for longer messages
When an SMS is too long, it’s automatically split into multiple message segments, which can affect readability and increase costs. If you frequently need to send longer messages, there are better alternatives that maintain clarity while enhancing engagement.
Here are some effective options for handling extended messages.
MMS messaging
MMS (Multimedia Messaging Service) allows you to send messages with images, videos, and audio, along with extended text. Unlike SMS, which is limited to plain text and strict character limits, MMS supports richer content and longer messages without being split into multiple segments.
As for SMS vs. MMS, each has its own use cases. Use SMS for short, text-based messages like alerts, confirmations and promotions.
MMS is better for sending images, GIFs, video content, or longer promotional messages. Overall, MMS is particularly useful for marketing campaigns, product promotions, and customer engagement, because visuals often lead to higher interaction rates compared to plain text.
Rich communication services
RCS (Rich Communication Services) is an upgraded messaging protocol available on Android devices, offering features like longer text limits, multimedia support, read receipts, and interactive buttons. It bridges the gap between SMS and messaging apps by providing a richer, more interactive experience without the traditional SMS limitations.
For businesses that require more flexibility, apps like WhatsApp, iMessage, and Facebook Messenger serve as great alternatives. These platforms allow for unlimited text, media sharing, and interactive elements, making them ideal for customer service, promotions, and brand engagement.
Separate long SMS messages
If SMS is the only option, segmenting longer messages properly ensures clarity and readability. Best practices include:
- Avoiding mid-word breaks—split messages at natural sentence endings.
- Ensuring logical flow—each part should make sense on its own.
- Using concise language—restructure content to fit within fewer segments.
For example, instead of: "Our new winter collection is here. Visit our website for exclusive deals. Enjoy 30% off all coats and boots this weekend only. Shop now at [link]."
Break it into:
- "Our new winter collection is here! Visit our site for exclusive deals."
- "Enjoy 30% off all coats & boots this weekend. Shop now: [link]."
Before sending an SMS campaign, businesses should test their message length to ensure it stays within the character limit and avoids unnecessary multi-part messages. Messages that exceed 160 characters may be split, increasing costs and potentially disrupting readability.
Using SMS character counters can help businesses check whether their SMS message length fits within the character limits and whether it contains Unicode characters that might reduce the available space.
These tools can also highlight when an SMS might switch to a Unicode text message due to special symbols, emojis, or formatting. By testing messages beforehand, businesses can optimize communication, reduce costs, and maintain SMS compliance.
Start crafting smarter SMS messages today
A well-optimized SMS strategy can make all the difference in reaching your audience effectively. Whether you're keeping messages concise, leveraging MMS for richer content, or ensuring SMS compliance, every detail matters.
With Mailchimp, you can take your SMS marketing even further. Our platform helps you segment audiences, personalize messaging, and automate campaigns—so you send the right message at the right time. Plus, with built-in tools and features to test SMS length and optimize content, you can avoid unnecessary costs while maximizing engagement. Ready to fine-tune your SMS strategy? Let Mailchimp help you craft messages that connect.
Key Takeaways
- Standard SMS messages have a maximum of 160 characters, but special characters and emojis can reduce this limit.
- Exceeding the character limit results in a multi-part message, increasing costs and affecting readability.
- MMS and RCS messaging offer alternatives for longer or more visually engaging content.
- Testing your SMS length before sending helps ensure SMS compliance and prevents unexpected charges.