Texting 101: The Basics of SMS FAQ
Whether you are new to SMS marketing or just need a refresher on the basics, this guide covers the core fundamentals of business texting. Use this guide to understand essential concepts like character limits, emojis, deliverability, mandatory auto-responses, and number management.
Definition of SMS
SMS stands for "Short Message Service." It is the official name for what is universally known as texting. It is a widely standardized protocol that allows mobile devices to exchange short text messages over cellular networks.
Standard SMS length and character limits
The industry-standard maximum for a single SMS message across all carriers and phones in the U.S. and Canada is 160 characters. While you can write longer messages, carriers will typically segment them into multiple 160-character blocks, which will cost additional message credits. Being quick and to the point is the primary advantage of SMS!
Impact of emojis and special characters
Adding an emoji or certain special characters changes the backend "encoding" of your message. Standard text uses GSM encoding (160 characters per message). Emojis and special characters require UCS-2 encoding. When your message switches to UCS-2 encoding, the character limit for a single SMS segment drops from 160 characters down to 70 characters.
Recipient compatibility and delivery speed
If a contact has a mobile phone, odds are they can receive texts! Furthermore, SMS is one of the most instantaneous forms of digital communication. Pending the occasional carrier network lag, messages are usually delivered to the recipient within seconds of hitting "send."
Factors influencing message deliverability
While text message delivery comes incredibly close to a sure thing (SMS boasts a 98% open rate industry-wide), 100% deliverability is never guaranteed. Carrier outages, unreachable phones (e.g., dead battery or out of cellular range), or carrier spam filters can occasionally prevent a message from being successfully delivered.
Mandatory HELP and STOP auto-responses
Both are mandatory auto-responses designed to keep your business texting legal and compliant:
- HELP: When a subscriber replies "HELP," your platform should automatically reply with an informative message providing customer support contact information (like an email or phone number) and instructions on how to opt out.
- STOP: When a subscriber replies "STOP" (or other universal opt-out keywords like CANCEL, UNSUBSCRIBE, or QUIT), they must be automatically unsubscribed from your list to remain compliant with industry regulations.
"Msg & Data Rates May Apply" disclosure
This is a mandatory disclosure phrase. Information about message and data rates must be presented to all subscribers when they first opt in, no matter what. It simply notifies the consumer that standard texting costs and cellular data limits set by their specific mobile phone plan will still apply to the messages they receive from you.
Personal number masking and Sender ID restrictions
It is not possible for mass business messages to appear as if they are coming from your personal cell phone number. However, you can personalize your texts by introducing yourself, using a dedicated business phone number, or utilizing a toll-free number or short code.
Account data and keyword retention during number changes
If you upgrade or switch your sending number (for example, moving from a standard 10-digit number to a dedicated short code), your data will be safely transferred to your new number. All of your contacts, lists, and past message history will remain intact. However, you may need to re-create or re-verify certain automated keywords if you switch to a short code.