SMS Character Limits & Message Segmentation

Last Updated: May 29, 2025

Overview

When sending SMS messages through TextBolt's Email to Text service, it's important to understand how messages

are segmented and charged. Telecom operators split messages into parts and charge for each part separately.

📝 Example for Demonstration Only - The following examples are provided for educational purposes to illustrate concepts and

are not part of the legal terms.

Healthcare Appointment Reminder:

"Dr. Johnson appointment tomorrow 2PM. Please arrive 15 min early. Reply STOP to opt out."

• Length: 87 characters • Segments: 1 • Billing: 1 message

IT System Alert:

"Server maintenance scheduled tonight 11PM-2AM. Systems will be unavailable. Contact IT for emergencies."

• Length: 102 characters • Segments: 1 • Billing: 1 message

Standard SMS Character Limits

Single SMS Segment

  • GSM-7 Encoding: Up to 160 characters

Unicode Encoding: Up to 70 characters

  • Unicode Encoding: Up to 70 characters

📝 Example for Demonstration Only - These examples illustrate character limits and are not part of the legal terms.

Maximum GSM-7 Single Segment (160 characters):

"Your account balance is $250.75. Last transaction: Gas Station $45.00 on 05/29. For support call 555-0123

or visit our website. Reply STOP."

Exactly 160 characters - fits in 1 segment

Maximum Unicode Single Segment (70 characters):

"Payment received! 💰 Thank you for your business. Order #12345"

70 characters with emoji - fits in 1 Unicode segment

Multi-Part Messages

When your message exceeds the single segment limit, it is split into multiple parts:

GSM-7 Encoding (Standard Characters):

  • 1st segment: 160 characters

  • 2nd segment: 153 characters (7 characters used for concatenation headers)

  • 3rd segment: 153 characters

  • Maximum: 306 characters (2 parts) or 459 characters (3 parts)

📝 Example for Demonstration Only - Multi-part GSM-7 message illustration:

Long Appointment Reminder (250 characters):

"Important: Your dental cleaning appointment with Dr. Smith is scheduled for Thursday, June 15th at 3:30 PM. Please

arrive 15 minutes early to complete any necessary paperwork. Bring your insurance card and ID. If you need to

reschedule, please call our office at 555-DENTAL (555-336-8251) at least 24 hours in advance. Reply STOP to opt out

of these reminders."

• Length: 250 characters • Segments: 2 • Billing: 2 messages

Unicode Encoding (Special Characters):

  • 1st segment: 70 characters

  • 2nd segment: 67 characters (3 characters used for concatenation headers)

  • 3rd segment: 67 characters

  • Maximum: 134 characters (2 parts) or 201 characters (3 parts)

📝 Example for Demonstration Only - Multi-part Unicode message illustration:

Marketing Message with Emoji (120 characters):

"🎉 Flash Sale Alert! Get 50% off everything today only! 🛍️ Use code SAVE50 at checkout. Free shipping on orders over

$75. Visit our store now! ⏰"

• Length: 120 characters • Segments: 2 (Unicode) • Billing: 2 messages

TextBolt Specific Limits

Through our system:

  • One SMS part: Up to 303 characters

  • Maximum message length: 909 characters (3 parts)

  • Messages exceeding 909 characters: Will be cropped

📝 Example for Demonstration Only - TextBolt limit illustration:

Message at TextBolt's 909 Character Limit:

"Emergency System Maintenance Notice: Our primary data center will undergo critical infrastructure upgrades this

Saturday, June 10th from 11:00 PM to 6:00 AM Sunday. During this maintenance window, all services including email,

web portal, customer databases, and phone systems will be completely unavailable. This maintenance is essential for

improving system reliability and security. We apologize for any inconvenience this may cause. For urgent matters

during the outage, please contact our emergency hotline at 1-800-EMERGENCY. All scheduled backups will be

completed before maintenance begins. Normal service will resume by 6:00 AM Sunday. We will send status updates

via our Twitter account @CompanyUpdates. If you have any questions or concerns about this maintenance, please

contact our support team before Friday at 5:00 PM. Thank you for your patience and understanding. Reply STOP to

opt out."

• Length: 909 characters • Segments: 3 • Billing: 3 messages

Character Encoding Types

GSM-7 Standard Characters

The GSM-7 character set includes:

  • All Latin letters (A-Z, a-z)

  • Digits (0-9)

  • Common punctuation: . , ! ? ' " - ( )

  • Special characters: @ £ $ ¥ è é ù ì ò Ç Ø ø Å å Δ _ Φ Γ Λ Ω Π Ψ Σ Θ Ξ

  • Space and line break

📝 Example for Demonstration Only - GSM-7 compatible messages:

✅ GSM-7 Compatible:

"Order #12345 shipped! Track at: company.com/track Cost: $29.99. Questions? Call 555-0123."

✅ GSM-7 with European Characters:

"Café reservations confirmed! Table for 4 at 7PM. Location: 123 Main St. Merci!"

Characters Requiring Unicode

Any character not in the GSM-7 set triggers Unicode encoding, including:

  • Emojis 😊

  • Smart quotes " "

  • Non-Latin scripts (Arabic, Chinese, Cyrillic, etc.)

  • Special symbols (™, ©, ®)

  • Mathematical symbols

  • Currency symbols other than £ $ ¥ €

📝 Example for Demonstration Only - Unicode-triggering characters:

❌ Unicode Required (Smart Quotes):

"Welcome to our "Premium" service! Enjoy exclusive benefits."

Character limit reduced to 70 per segment due to smart quotes

❌ Unicode Required (Trademark Symbol):

"Try our new ProductName™ today! Available in stores nationwide."

Character limit reduced to 70 per segment due to ™ symbol

❌ Unicode Required (Emoji):

"Thanks for your purchase! 🎉 Your order will arrive tomorrow."

Character limit reduced to 70 per segment due to emoji

Important: Using even ONE Unicode character converts the ENTIRE message to Unicode encoding, reducing

your character limit from 160 to 70 per segment.

Message Segmentation Examples

📝 Examples for Demonstration Only - The following examples illustrate message segmentation concepts and are not part of the

legal terms.

Example 1: GSM-7 Single Segment

Message: "Sale today! Get 20% off all items. Visit our store at 123 Main St. Reply STOP to opt out."

  • Length: 89 characters

  • Segments: 1

  • Character set: GSM-7

  • Billing: 1 message per recipient

Example 2: Unicode Single Segment

Message: "Flash sale! 🎉 Get 20% off today only!"

  • Length: 38 characters

  • Segments: 1 (but counts against 70-character Unicode limit)

  • Character set: Unicode (due to emoji)

  • Billing: 1 message per recipient

Example 3: Multi-Part GSM-7

Message: "Important appointment reminder: Your appointment with Dr. Smith is scheduled for tomorrow, June

18 at 2:30 PM. Please arrive 15 minutes early for check-in. If you need to reschedule, call 555-0123. Reply

STOP to opt out."

  • Length: 221 characters

  • Segments: 2 (counts as 2 messages for billing)

  • Character set: GSM-7

  • Billing: 2 messages per recipient

Example 4: Real-World Business Scenarios

Restaurant Reservation Confirmation:

"Your table for 4 at Tony's Pizza is confirmed for tonight at 7:30 PM. Address: 456 Oak Ave. Phone: 555-PIZZA.

Please call if running late. Reply STOP to opt out."

• 161 characters • 2 segments • GSM-7 encoding

Delivery Notification:

"Your Amazon package has been delivered! 📦 Check your front door. Order #ABC123456789. Thank you for

shopping with us!"

• 119 characters • 2 segments • Unicode encoding (due to 📦 emoji)

Banking Security Alert:

"SECURITY ALERT: Login attempt from new device detected on your account at 3:45 PM EST. If this was you,

ignore this message. If not, call 1-800-BANK-NOW immediately. Never share your login details."

• 203 characters • 2 segments • GSM-7 encoding

Billing Implications

Important: Each message segment is billed separately:

  • Sending one 200-character message = 2 billable messages

  • Sending one message to 10 recipients = 10 billable messages

  • Sending one 200-character message to 10 recipients = 20 billable messages

📝 Example for Demonstration Only - Billing calculation scenarios:

Scenario 1: Short Message to Multiple Recipients

Message: "Meeting moved to 3PM today." (30 characters)

Recipients: 25 staff members

Billing: 25 messages (1 segment × 25 recipients)

Scenario 2: Long Message to Multiple Recipients

Message: 300-character policy update

Recipients: 100 employees

Billing: 200 messages (2 segments × 100 recipients)

Scenario 3: Unicode Message to Large Group

Message: "Congratulations! 🎉" + 120 characters of text

Recipients: 500 customers

Billing: 1000 messages (2 Unicode segments × 500 recipients)

Character Count Tool

We provide a Character Count Tool on our website to help you:

  • Check your message length

  • See how many segments your message will use

  • Identify Unicode characters that may reduce your limit

  • Optimize your message before sending

Best Practices

Keep Messages Concise

  • Aim for under 160 characters when possible

  • Remove unnecessary words

  • Use common abbreviations your audience understands

📝 Example for Demonstration Only - Message

optimization:

❌ Verbose (180 characters):

"We would like to inform you that your scheduled

appointment for tomorrow has been moved to a different

time slot due to scheduling conflicts."

✅ Concise (65 characters):

"Appointment moved to 3PM tomorrow. Call 555-0123 to

confirm."

Avoid Unicode Triggers

  • Use standard punctuation instead of smart quotes

  • Avoid emojis unless necessary

  • Check for hidden Unicode characters from copy-

    paste

📝 Example for Demonstration Only - Unicode avoidance:

❌ Unicode (70 char limit):

Use "straight quotes" not "smart quotes"

✅ GSM-7 (160 char limit):

Use "straight quotes" not "smart quotes"

Test Before Sending

  • Use our Character Count Tool

  • Send test messages to yourself

  • Verify message appears as intended

  • Check segment count for billing

Message Optimization Tips

  • Front-load important information

  • Include opt-out instructions at the end

  • Use URL shorteners for long links

  • Avoid special formatting characters

  • Keep business name short

📝 Example for Demonstration Only - Well-optimized message structure:

Optimized Structure:

"[URGENT] Server maintenance tonight 11PM-2AM. Systems offline. Emergency: call 555-0123. More info:

bit.ly/maint2025 Reply STOP to opt out."

• Key info first • Contact provided • Short URL used • Opt-out included • 133 characters

Technical Details

GSM-7 Extension Characters

Some characters count as TWO characters:

^ {} \ [ ] ~ | €

Plan accordingly when using these

📝 Example for Demonstration Only - Extension character impact:

Message with Extension Characters:

"Price: €25.99 {includes VAT} [see terms] Visit: www.site.com/path~123"

• Appears as 64 characters but counts as 70+ due to extension characters

• € { } [ ] ~ each count as 2 characters

Alternative Without Extension Characters:

"Price: 25.99 EUR (includes VAT) see terms at www.site.com/path123"

• 68 standard characters, more efficient character usage

Line Breaks

  • Line breaks count as 2 characters

  • Avoid excessive formatting

  • Keep messages in paragraph form

📝 Example for Demonstration Only - Line break impact:

❌ Multiple Line Breaks (wastes characters):

Meeting Update: Time: 3PM Date: Tomorrow Room: Conference A Please confirm attendance.

• 5 line breaks = 10 extra characters

✅ Efficient Format:

Meeting Update: Tomorrow 3PM in Conference A. Please confirm attendance.

• Same information, fewer characters

Support

For questions about character limits or message segmentation:

  • Email: support@textbolt.com

  • Include your message content for analysis

  • We can help optimize your messages

This document is part of TextBolt's service documentation. Character limits and segmentation rules are determined by

telecom industry standards and carrier requirements. All examples provided are for demonstration purposes only and

are not part of the legal terms.