United States SMS Guide - sms-compliance -

Frequently Asked Questions

Use a registered short code or 10DLC long code with a reputable SMS API provider like Twilio, Sinch, MessageBird, or Plivo. Ensure compliance with TCPA and CAN-SPAM regulations by obtaining explicit consent before sending marketing messages and respecting quiet hours.
10DLC (10-digit long code) is the standard for Application-to-Person (A2P) messaging in the US. It requires registration with The Campaign Registry to improve deliverability and compliance. It's suitable for various use cases like two-factor authentication, customer service, and transactional alerts.
A2P 10DLC registration helps combat spam and fraud, improving message deliverability and trust. It provides carriers with sender information, allowing them to better filter unwanted messages and ensure legitimate traffic reaches consumers.
Use short codes for high-volume marketing campaigns and time-sensitive alerts due to their higher throughput. Use 10DLC long codes for lower-volume applications like two-factor authentication, customer service interactions, and transactional messages.
SMS to landlines is possible but not always reliable. Some carriers convert the message to a voice call, while others may not deliver it at all. Verify number types and consider filtering landlines from SMS campaigns.
Single SMS messages are limited to 160 GSM-7 characters or 70 UCS-2 characters (for special characters). Concatenated messages can contain up to 1600 characters before splitting into segments.
Comply with TCPA and CAN-SPAM by obtaining explicit written consent, honoring opt-out requests within 24 hours, respecting quiet hours (9 PM - 8 AM local time), and registering for A2P 10DLC when using long codes.
You must support STOP, UNSUBSCRIBE, CANCEL, END, QUIT for opt-out and HELP or INFO for program details. These keywords should function in both upper and lower case.
Carriers filter messages to block spam, prevent fraud, and protect consumers from unwanted content. Common triggers include prohibited content (SHAFT), suspicious URLs, excessive punctuation, and all-caps messages.
Obtain clear and conspicuous consent through affirmative action, such as checking a box or sending a keyword. Document and store consent details including timestamp, source, and opt-in method for compliance.
Keep messages concise, include a clear call-to-action, personalize content thoughtfully, maintain consistent brand voice, and always respect quiet hours and frequency limits. Thorough testing and monitoring are also recommended.
Concatenated SMS messages in the US can contain up to 1600 characters before being split into segments. Each segment is limited to 160 GSM-7 characters or 70 UCS-2 characters if special characters are used.
Businesses must check the National Do Not Call Registry every 31 days and remove any registered numbers from their marketing lists. Maintain internal do-not-contact lists as well.
Violating TCPA regulations can result in significant fines, legal action, and reputational damage. Ensure strict compliance with all guidelines, including obtaining proper consent and honoring opt-out requests.
Loading...