Best Practices for Business SMS Messaging


This document covers Plum Voice’s recommendations for SMS messaging campaigns using Plum products. Topics include background info on the policies and regulations on SMS messaging, why and how messages might be filtered, and what steps to take to avoid filtering of your messages.

Background: Carrier Policies and Industry Regulations

Each wireless provider – AT&T, Verizon, T-Mobile, and so on – sets compliance policies for the types and behavior of traffic permitted on their networks. Provider policies for messaging have evolved rapidly since ten-digit long code (10DLC) was accepted as a number type for business application-to-person (A2P) messaging in 2019.

Industry-wide regulations were set for A2P SMS and MMS messaging by CTIA. This led to providers and other telecom vendors developing their own A2P policies to 1) ensure regulatory compliance on their networks (this often involves A2P 10DLC registration status) and 2) protect their wireless users from unwanted messaging.

A2P messaging may pass through several different providers and vendors to reach a recipient. This means that throughout its journey, a message must be compliant with each provider and vendor A2P policy. Noncompliant messaging risks policy enforcement measures, including message filtering.


How does message filtering happen?

While wireless providers do not disclose their exact tools and mechanisms, machine learning software is widely reported to be used for automatic message filtering. Messaging traffic determined to be unwanted and/or noncompliant with a provider’s A2P policies are at most risk of being filtered.

My business uses A2P messaging to communicate with customers. How can we avoid filtering?

While no 100% guaranteed methods exist – providers and vendors set their A2P policies and filtering systems at will – Plum Voice recommends the following best practices based on CTIA guidance, provider and vendor policy disclosures, and our observations of successful SMS messaging through our vendors.

Message contents

CTIA guidance

Additional resources

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