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10DLC messaging best practices to prevent being suspended or blocked

Note: This article is meant to help you follow the best practices for A2P messaging, but it doesn't constitute legal advice. All messaging traffic is required to comply with relevant laws and regulations, including, but not limited to, the Telephone Consumer Protection Act (TCPA). 

The US carriers introduced substantial fines from the start of 2024 for non-compliant traffic that represents the most harmful violation to consumers, specifically (and not exclusively limited to):

  • Phishing, smishing, and social engineering (targeting individuals in a way that manipulates them to reveal private information).

  • Illegal content such as cannabis, illegal prescriptions, and/or other similar.

  • Violations of content related to SHAFT and/or other similar.

Any fines will be passed on to customers determined to be infringing.

The following list includes best practices and guidelines for different A2P messaging use cases. 

Principle Description


The consumer must give appropriate consent. 

Make sure users explicitly say they want messages from you.  The single most important practice is ensuring you have accurate, reliable consumer opt-in specific to the type of messages you are sending consumers. Generally, opt-out rates are consistently low when you have obtained reliable and clear consumer opt-in consent. At any time, Clickatell or wireless carriers may require evidence from you (or your customers) of documented opt-in consent for a particular message.
Single number use 

Utilize a single number for identity.

Don’t spread your campaigns over several numbers.  Using a single number for both text and voice calls is not only a best practice, but it’s also a better overall user experience. Avoid spreading messages across many source phone numbers, specifically to dilute reputation metrics and evade filters. This is referred to as “snowshoeing” and can result in your content being blocked. If your messaging use case requires the use of multiple numbers to distribute “similar” or “like” content, please discuss this with your Clickatell rep (or other carrier rep).
Brand identification  Identify the brand or business in the body of the message.  Your application, service, or business name should be included in the content of the body.  Example: [Your Business Name]: You have an appointment for Tuesday 3:00PM, reply YES to confirm, NO to reschedule. Reply STOP to unsubscribe.
Adherence to sample messages It is crucial for your messages to strongly match the sample messages submitted. It may be considered non-compliant if the content of messages does not closely match the samples submitted during the campaign registration process. In the event that checks are performed and the messages are significantly different, the service may be blocked or disabled.
Opt-in confirmation Let users know they have opted in to receive messages from you.  Upon successful opt-in by a mobile subscriber, an opt-in confirmation message will immediately be sent to the mobile subscriber number. Per the CTIA Messaging Principles and Best Practices, “a single opt-in confirmation message displaying information verifying your customer’s enrollment in the identified program and describing how to opt-out” should be sent.  Example: Clickatell Product Trial Alerts: Welcome to Clickatell Trial Alerts! Msg&data rates may apply. Recurring Messages. Reply HELP for help, STOP to cancel.  Clickatell recommends sending your opt-in confirmation message or HELP message (see below) once a month or every 6 messages so customers know how to opt out and how to reach the business if they have questions. 

Support for STOP 

Use of opt-out language.

Make sure your users can opt out of receiving messages.  The best practice is notifying the consumer of their ability to opt out from future messages from the message sender. This is especially important when sending informational or promotional messages.  An example would be to include the sentence, “Reply STOP to unsubscribe” at the end of the initial message sent to the consumer, or “reply STOP to cancel”.
Processing HELP keywords  HELP commands should present a clear way for the end user to identify information about the message sender and how to opt-out if necessary. HELP must be managed by the customer – there's no network-level processing of HELP. Clickatell recommends the response to a HELP command includes the following: 
  • Business name and description.
  • Contact info (TN, TFN, or email) for the business.
  • Language about any associated fees or charges.
  • Instructions on how to opt out.
Example: Clickatell Employee Alerts: Help at 812-345-6789. Msg&data rates may apply. Reply STOP to cancel.
Single domain  Use a single domain for URLs in your messages.  Each campaign should be associated with a single web domain owned by the customer.   Although a full domain is preferred, a URL shortener may be used to deliver custom links. You should avoid the common, public, or shared domain shorteners, such as:
  • .xyz 
Examples of good URLs: 
  • .com
  • .gov
  • .org
  • branded shortened URLs

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