Technical Info

Technical Information

Types of Mobile Messaging

Mobile communication today primarily includes:

  • SMS (Short Message Service)
  • MMS (Multimedia Messaging Service)
  • RCS (Rich Communication Services)
  • Email
  • Application-to-Person (A2P) Messaging & Short Codes
Each type is described below.

SMS (Short Message Service)

SMS is the most widely supported mobile messaging standard and works on virtually all mobile phones.

Message Length

SMS messages are limited by byte size, not simply character count:

  • GSM-7 encoding (standard Latin alphabet)

    • Up to 160 characters per single-part message
  • Unicode (UCS-2) encoding (used when messages contain emojis, accented characters, or non-Latin scripts such as Arabic, Chinese, Cyrillic, etc.)

    • Up to 70 characters per single-part message
If a message exceeds these limits, it is automatically split into multiple segments (concatenated SMS).

Concatenated (Multipart) SMS

When messages exceed the single-part limit:

  • GSM-7 multipart SMS: 153 characters per segment
  • Unicode multipart SMS: 67 characters per segment
Each segment may be billed separately by the carrier.

Note: The presence of emojis, smart quotes, or special symbols may cause the message to be encoded in Unicode, reducing the character limit.

MMS (Multimedia Messaging Service)

MMS allows users to send multimedia content such as:

  • Images
  • Audio files
  • Video clips
  • Text with media attachments
Key Characteristics

  • MMS messages have larger size limits than SMS, but the maximum size varies by carrier and country.
  • Media may be compressed or resized automatically by the sending device or carrier.
  • Delivery speeds depend on mobile data connectivity.
  • Carrier compatibility and supported file formats may vary.
Message size limits, delivery behavior, and applicable fees are determined by the recipient’s and sender’s mobile carriers.

RCS (Rich Communication Services)

RCS is a modern messaging protocol designed to enhance SMS and MMS functionality.

Features may include:

  • Read receipts
  • Typing indicators
  • High-resolution media sharing
  • Wi-Fi messaging
  • Group chat enhancements
RCS is supported on many Android devices and carriers and may be available on other platforms depending on carrier and device support.

RCS functionality depends on:

  • Carrier support
  • Device compatibility
  • Internet connectivity
If RCS is unavailable, messages are typically delivered via SMS or MMS.

Email to Mobile

Many mobile devices allow users to send and receive email.

Messages sent to email addresses are transmitted over the internet rather than via SMS or MMS protocols. Delivery speed and availability depend on internet connectivity and the email provider.

When sending multimedia content, users may choose to send via MMS or email depending on their device and service configuration.

A2P Messaging (Application-to-Person)

A2P messaging refers to messages sent from businesses or applications to mobile users. These messages may include:

  • Account notifications
  • Two-factor authentication (2FA)
  • Customer support updates
  • Marketing or promotional messages
A2P messages may be delivered using:

  • 10-digit long codes
  • Toll-free numbers
  • Short codes (5–6 digit numbers)
  • Registered sender IDs (in supported countries)
Carrier registration and compliance requirements apply in many regions.

SMS Encoding Reference

GSM-7 Encoding

Message Type Character Limit
Single-part 160 characters
Multipart (per segment) 153 characters
Unicode (UCS-2) Encoding

Message Type Character Limit
Single-part 70 characters
Multipart (per segment) 67 characters
Special characters (e.g., €, emojis, non-Latin alphabets) may trigger Unicode encoding and reduce message length.

“Message and Data Rates May Apply”

“Message and data rates may apply” means that your mobile carrier may charge you for sending or receiving messages according to your individual mobile service plan.

Charges may include:

  • Per-message SMS or MMS fees
  • Data usage charges
  • Premium service charges (if applicable)
Please consult your mobile carrier directly for details regarding your specific plan.

We do not control and are not responsible for carrier-imposed charges.

Premium Messages & Short Codes

Premium or subscription-based messages may be sent from short codes (typically 5–6 digit numbers) or designated premium numbers.

These services may involve:

  • One-time charges
  • Recurring subscription charges
  • Donation-based billing
  • Content purchases
Important Consumer Information

  • Subscription services require prior user consent.
  • Message frequency and pricing must be disclosed at sign-up.
  • Users may opt out by replying STOP where supported.
  • Users may request help by replying HELP where supported.
If you believe you have been subscribed unintentionally, contact your mobile carrier immediately.

User Privacy & Consent

Mobile messaging services typically require:

  • Clear user opt-in consent before receiving recurring marketing messages
  • Transparent disclosure of message frequency
  • Clear opt-out instructions
We recommend that users review:

  • The privacy policy of any service they subscribe to
  • The terms and conditions of messaging programs
  • Their mobile carrier’s billing policies
Important Disclaimer

Mobile messaging services depend on:

  • Carrier infrastructure
  • Device compatibility
  • Network availability
  • Geographic location
Delivery is not guaranteed and may be delayed or blocked due to carrier filtering, device limitations, or regulatory requirements.

For questions about your mobile billing or messaging capabilities, please contact your mobile carrier directly.