SMS Best Practices for Outbound Call Centers: How to register campaigns, improve deliverability, and support compliance

When it comes to your outbound SMS marketing campaigns you may be wondering: Are my text messages to leads reaching their targets? Are my SMS numbers getting blocked? How do I improve SMS delivery rates? How can I send text messages that are in compliance? 

You’re up-to-date with current outbound trends, and use omnichannel marketing to reach out over multiple channels. You’re not just relying on your predictive dialer to reach leads over your voice channel. You’re employing email and taking advantage of SMS tools to contact leads via text message.

In this post, we’re looking at outbound SMS best practices for call centers, and why it’s recommended that you register your SMS traffic to improve message deliverability and avoid unnecessary blocking as well as fees for being out of compliance.


How is compliance in the SMS Industry monitored?

Compliance monitoring in the SMS industry has evolved by leaps and bounds over the recent years.

In addition to all service providers and pass-throughs using spam monitoring software, registration governing bodies have been set up, such as The Campaign Registry (TCR) to provide a database of registered SMS campaigns. When campaigns are blocked, they are blocked by the carriers (cell phone providers) or pass throughs themselves, not by TCR.

Each mobile operator (AT&T or T-Mobile, for example) has issued their own set of guidelines and grading systems for how A2P 10DLC (formerly Local SMS) traffic is graded. 

A2P 10DLC SMS vs. A2P Toll-Free SMS 

A2P 10DLC SMS [Application-to-Person (A2P)]

A2P 10DLC (formerly Local SMS) offers users the ability to significantly increase their deliverability rates as well as send content that was previously prohibited. For example, A2P 10DLC allows you to send embedded links, embedded phone numbers and more as part of your messaging content. In order to use A2P 10DLC, you must register your traffic through your call center service provider with The Campaign Registry (TCR). If you do not register your SMS traffic, it will be subjected to blocking at increasingly higher rates, unregistered traffic fees, and even suspension of your SMS service. 

A2P Toll-Free SMS [Application-to-Person (A2P)]

This is the channel used for sending and receiving SMS messages using Toll-Free numbers. Since it was designed with commercial traffic in mind, A2P Toll-Free SMS gives users a higher average throughput and daily limit for sending messages versus A2P 10DLC. It is very important to consider that you are only allowed to have 1 Toll-Free SMS number sending messages from a campaign. If you attempt to use multiple toll-free numbers on the same campaign, the industry will view this as “snowshoeing”. Snowshoeing is defined in the industry as “spreading similar messages across multiple numbers as a way to avoid per number rate limits and volume limitations”. A2P Toll-Free SMS also requires you to complete a registration process. However, the process for registering Toll-Free SMS traffic is not as formal and regulated as the registration process for A2P 10DLC. You are required to maintain full opt-in records, complete with time-stamps and IP addresses, as well as provide a way for leads to opt-out at any time they see fit.


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How do I know if my SMS messages are compliant?

Both A2P 10DLC and A2P Toll-Free SMS campaigns are now required to state their brand name in their messaging content. Mobile operators and their partners in the industry are making this a requirement so their subscribers have a more clear picture of who exactly they are communicating with. Short-hand versions of your full legal brand name are acceptable. For example, if a company whose full legal Name was “ABC Healthcare Experts” wanted to state their brand in their messages, they could use the short-hand version of “ABC Health” to remain compliant.

For A2P 10DLC, mobile operators like AT&T and T-Mobile have created individual grading systems and guidelines that must be followed when sending A2P 10DLC traffic to their subscribers. Each carrier’s grading system and guidelines are discussed in more detail below.

T-Mobile (including Sprint) SMS

T-Mobile classifies registered brands and campaigns using “Brand Tiers” that range from “Top” to “Low”. These classifications, combined with third-party vetting scores (optional), help define your throughput for sending messages to T-Mobile.

T-Mobile sets daily limits for how many messages you can send to their network. Daily limits range from 2,000 to 200,000 messages per day. They also require a special provisioning process for use of a number pool. A number pool is any registered campaign that needs to use 50 or more numbers to send its messages. 


AT&T classifies registered brands and campaigns using “Message Classes” that range from “A” to “Y”. These classifications, combined with third-party vetting scores (optional), help define your throughput for sending messages to AT&T subscribers. There are a total of 16 different message classes. 

Unlike T-Mobile, AT&T does not place a daily limit on the amount of messages you can send to their network. Rather, they place restrictions on how many SMS messages you can send to their network per minute. Text per minute limits range from 75 up to 4,500 texts per minute.

Verizon Wireless SMS

Verizon still currently abides by the CTIA Monitoring Handbook as their code of conduct. It’s very important that 10DLC campaigns maintain good opt-in and opt-out practices. Calls-to-action, terms and conditions, and privacy policies need to be made clear during communication with any Verizon Wireless subscriber. This will help prevent spam complaints. Strict spam monitoring is in place and Verizon has a zero-tolerance policy for any campaigns deemed to be perpetuating spam or fraudulent traffic, especially Phishing. Campaigns involved with these kinds of incidents will be globally blocked by Verizon immediately.


What new content does A2P 10DLC & A2P Toll-Free SMS allow you to use?

A2P 10DLC gives SMS users the ability to send new and previously prohibited content on Local SMS. You can now utilize all of the following campaign attributes in your registered messaging content:

  • Subscriber Opt-In (Required)
  • Subscriber Opt-Out (Required)
  • Subscriber Help (Required)
    Number Pooling (Additional Provisioning Required For T-Mobile)
  • Direct Lending or Loan Arrangement
  • Embedded Phone Number
  • Affiliate Marketing
  • Age-Gated Content

What’s still prohibited?

Even given all of the new things you can do with your messaging content, A2P 10DLC and A2P Toll-Free SMS does not offer support for every use-case. Certain use-cases, like sweepstakes, tax relief and credit repair, may be on a best-effort basis. Meaning some carriers may allow the traffic and some may not. These use-cases are best-effort because they have a history of generating a high volume of end user complaints. It is best to discuss your use-case in detail with your service provider during registration. 




How can I mitigate the risk of SMS messages getting blocked?

Answer:  Register your SMS traffic.

Registering traffic is the only way moving forward to mitigate the risk of your messages getting blocked.

Ensuring your company is registered as a brand and that your messaging content is registered as a campaign will mitigate your risk for unregistered traffic fees, message blocking/filtering and unlocks the use of the content discussed in the previous section. Subscriber Opt-in, Subscriber Opt-out and Subscriber help are all required functionalities for A2P 10DLC & A2P Toll-Free SMS campaigns. A2P 10DLC requires that you only allow 1 opt-in per campaign, and opt-ins are not transferable to any other campaign. Avoiding a high opt-out rate will also mitigate your risk of having your messages flagged and blocked by the destination mobile providers. 


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Outbound SMS Solutions

Both A2P 10DLC and A2P Toll-Free SMS give registered users the ability to engage with their customers in new and exciting ways. 


A2P 10DLC gives you the ability to send content using local numbers that was previously prohibited. It gives users the ability to have up to 49 registered numbers for a campaign. This allows users to keep their local presence in the states where their businesses are located. Subscriber Opt-in, Subscriber Opt-out and Subscriber help are all required functionalities for A2P 10DLC SMS campaigns. You must also remember to state your brand, even in short-hand form, in your messaging content so the customers you are texting are clear on who they are communicating with. A2P 10DLC requires that you only allow 1 opt-in per campaign and opt-ins are not transferable to any other campaign. Avoiding a high opt-out rate

A2P Toll-Free 

A2P Toll-Free gives registered users the ability to send messages at a higher volume on average daily. However, you are only permitted to use one registered Toll-Free SMS number per campaign. Subscriber Opt-in, Subscriber Opt-out and Subscriber help are all required functionalities for A2P Toll-Free SMS campaigns. You must also remember to state your brand, even in short-hand form, in your messaging content so the customers know exactly who they are communicating with.  


Outbound SMS is a powerful tool for driving more conversations

With open rates of up to 98 percent, text messaging is one of the most effective tools for reaching your audience. Unlike junk mail, spam, or adverts that can be ignored, people tend to read every text they receive. 

SMS is potentially the safest outreach channel right now 

Ever since the Supreme Court’s 2021 ruling in the Facebook v. Duguid case, SMS may be the safest outreach channel in most states. As calls get flagged and blocked by carriers, and litigators hash out legal disputes over outbound calling, many call centers continue to turn to SMS as an important tool in their outreach arsenal.

Still, to help minimize your risk while using SMS, Contact Center Compliance recommends scrubbing your data for litigators, establishing a DNC policy and process, and ensuring that you possess the right consumer consent. Additionally, a tool like Convoso’s StateTracker™ can help keep your  compliance strategy up-to-date even as individual states introduce new laws across the country.

Increase conversion rates for outbound campaigns

Automated SMS uses smart triggers to automatically send a text based on call count, phone call outcome, or any value populated in the lead record. With dynamic fields you can customize text messages to leads for a more engaging experience.

Boost your sales with 2-way SMS

Give your agents the ability to send texts to leads promoting your product or service. Then, receive responses indicating interest. Two-way messaging is also a simple and effective way to schedule callback times.

What about IVA/Conversational AI?

Conversational AI products such as Convoso’s will also be subject to SMS laws and legislation. In fact, the Campaign Registry is very strict on what types of campaigns are permitted to be texted/dialed in an outbound environment by AI. As a result, it is always recommended to seek legal counsel when planning to enable your outbound campaigns with conversational AI solutions for SMS and voice.

Nevertheless, an AI SMS solution like can be a potent tool for driving greater efficiency and more contacts for your lead gen or outbound sales operation. Automate routine conversations at scale and let your agents focus more on closing sales with qualified leads. Learn more today.

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