Avoid Spam Filters for SMS: 15 Actionable SMS Best Practices + Off-Limits Spam Words

Avoid Spam Filters for SMS: 15 Actionable SMS Best Practices + Off-Limits Spam Words Featured Image

Ensure Effective, Honest Texts That Reach Your Customers

When crafting text messages to consumers, it’s crucial to avoid spam filters to ensure message deliverability and brand trust. However, avoiding spam triggers from carrier algorithms can be challenging, especially when using certain “flagged” words. 

In this blog, we’ll show you how to establish a safer context and minimize the risk of your messages being marked as spam.


15 Best Practices to Avoid Spam Filters

Whether you’re using promotional (one-way) or conversational (two-way) SMS, avoid spam filters by employing best practices in every message. 

Both promotional and conversational SMS can still be flagged as spam if they contain certain trigger words or patterns, so it’s essential to craft them carefully and employ SMS best practices whenever you’re texting customers.

Here are 15 vital SMS best practices to understand and implement:


SMS Best Practices for Message Content

Context, context, context!

When it comes to spam filters, keep in mind that context is what matters the most. 

Spam filters have become more sophisticated, and can now analyze the context in which you use these words. Many spam words are considered spammy only when used in a particular context.

Make it clear why the recipient is receiving the message and how it benefits them. Mention previous interactions or purchases to create a se

SMS exchange

nse of continuity. For example:

  • Instead of “Get a free gift,” use “Thank you for being a loyal customer! Enjoy a complimentary gift with your next purchase.”

Be as clear as possible

Ensuring your messages are transparent and straightforward will help them avoid spam filters. Always avoid deceptive or exaggerated claims. 

For instance:

  • Instead of “Win a free iPhone now!” use “Enter our contest for a chance to win an iPhone.”

Even in a conversational context, avoid words and phrases that are commonly flagged as spam. Instead, focus on creating value and relevance in your messages.

By focusing on clarity and value, you can use necessary promotional words while reducing the likelihood of being flagged as spam.


Avoid common spam trigger words

Familiarize yourself with words and phrases commonly flagged as spam. Some of these words are not immediately obvious—for example, did you know that “fantastic” can trigger spam filters?

Some words are only considered spammy when used in the wrong context. Though context is still the most important thing, be aware of common spam triggers and avoid them if possible. 

To give you an idea, here are some examples of common spam categories and trigger words. Find our more comprehensive list here.


Example Spam Trigger Words 

Financial spam words Freebies spam words* FOMO spam words
Best price Free access Urgent
$$$ Free money Don’t delete
Refinance Free quote 4U
Extra cash Free trial You have been selected
Fast cash Free $$$ This won’t last


“Miracle worker” spam words No obligation/tricks/hidden fees spam words General use spam words
Reverse aging No cost Please read
Cures No catch Congratulations
Risk-free Not junk Social security number
100% satisfied No BS XXX
Weight loss Cancel anytime Compare rates

*You can use “free” in texts  if you do it in moderation. Do not overuse it or make exaggerated claims of a financial nature, as spam filters will most likely catch it.

Visual representation of debt


Avoid sending long messages

SMS is convenient and effective because the messages are short and easy to read. Stick to messages that are 320 characters or less.

If you need to send out a longer message, email is likely the better choice.


Keep messages error-free

People associate spelling and grammar mistakes with poor service and fraud. Error-free messages are more likely to avoid spam filters and resonate with recipients.

Ensure your message is grammatically correct and well-structured with correct spelling. 


Don’t overuse exclamation marks, CAPS, emojis, or special characters

Exclamation marks (!), all CAPS, emojis, and special characters can trigger spam filters. 

It’s a good rule of thumb to avoid exclamation marks, CAPS, and special characters unless they are necessary. Emojis can be used sparingly.


  • Initial Message:
    • Spammy Version: “GET FREE DEALS NOW! CLICK HERE!”
    • Better Version: “Hi [Name], we noticed you enjoyed our summer sale last year. Would you like to know about similar upcoming offers? Reply YES for more details.”
  • Follow-Up Message:
    • Spammy Version: “LIMITED TIME OFFER! BUY NOW!”
    • Better Version: “Hey [Name], it’s [Your Name] from [Brand]. Just wanted to let you know we have a special discount on your favorite items. Interested in learning more?”

Avoid spam filters by reducing use of emojis and special characters

Avoid SHAFT use cases

SHAFT is an acronym that stands for sex, hate, alcohol, firearms, and tobacco. For moral and legal reasons, the Cellular Telephone Industries Association (CTIA) will reject SMS or MMS that contain content on these topics. 

Content on gambling is also disallowed by the CTIA. In addition, vaping-related content will be blocked. Endorsement of illegal or illicit drugs, including cannabis, is prohibited.

Whenever possible, do not mention these subjects, or your messages will more than likely be blocked by carriers.

For companies that sell alcohol or tobacco, age-gating is required for consumers opting in to SMS marketing. 


Don’t ask private data collection questions

Avoid asking private data collection questions unless this is necessary, as this can look suspicious. For example, “social security number” is a common spam trigger word.

If asking for private information is necessary, don’t ask for it in the initial message. Let the recipient know who you are and establish context before asking for more information.

Your initial message should identify your company as the sender and include opt-out information.


Respect customer preferences

Keeping customer respect top-of-mind is a vital best practice for SMS, helping to build trust and minimize spam complaints. 

For regulatory compliance, companies must:

  • Clearly identify themselves
  • Provide an easy way to opt-out
  • Provide an easy way to get help

Clear opt-outs or options to change preferences not only comply with regulations but also reduce spam complaints. For example, a text that says, “Reply STOP to unsubscribe.” 


Leverage MMS

Multimedia messaging service (MMS) can provide images, gifs, or video media. To make messages more dynamic and appealing, incorporate multimedia elements through MMS.

For promotional SMS, switching it up from text-only can help boost conversion rates. 51% of customers are more likely to convert from SMS marketing ads if the message contains media. 


Actionable and High-Level SMS Best Practices

Test messages

Testing message content is a big part of success for any form of communication, including SMS. Before sending a batch of messages, test different versions to see which ones pass through spam filters. 

Use A/B testing to determine the most effective and least spammy phrasing for messages.

For more conversational texts, you should still test different messages to see what resonates best. Experiment with different conversational styles and monitor which ones lead to better engagement without triggering spam filters.

Message not delivered

Monitor deliverability

Keeping a close eye on deliverability rates is very important to maintaining and improving deliverability. If a particular message gets flagged frequently, revise your approach.

You should also keep track of opt-out rates, and take note of any spikes in opt-outs. If a particular message leads to high opt-out rates, you should analyze that content and make changes.

You should also pay attention to conversion rates for each message, as well as direct feedback from recipients. 

At Verse, we closely monitor deliverability for all of our clients’ messages and flag any dips in deliverability or opt-out rates.


Personalize messages

Personalized messages are less likely to be marked as spam. Improve read rates and engagement with targeted messaging based on known customer data such as purchase history, demographics, and intent.

Use the recipient’s name and, if applicable, reference any previous conversations.

  • Example: “Hi [Name], as a valued member, we have a special offer just for you.”

If engaging in a two-way conversation, you can establish a rapport with the recipient by personalizing messages and showing genuine interest in their preferences and behavior.

You can also segment your audience to tailor your messages based on customer behavior and preferences; this can make texts more relevant and engaging.


Encourage engagement

When speaking to customers, it’s always better to talk with them rather than at them. 

78% of people wish they could have a text conversation with a business—but only 13% of businesses enable recipients to respond to their SMS messages.

Utilize two-way SMS and interactive messages whenever possible, giving the recipient the opportunity to reply. 

With conversational SMS, encourage engagement by asking questions that require more than a yes/no answer. This can foster a dialogue and make the interaction feel more personal.

Even if using primarily promotional messaging, keep things open to conversation. By focusing on a friendly, personalized, and engaging conversational style, you can use promotional language in a way that feels natural and reduces the likelihood of being flagged as spam.

For example: 

  • Spammy Version: “WIN CASH PRIZES! ENTER NOW!”
  • Conversational Version: “Hi [Name], we’re hosting a fun giveaway for our loyal customers. What kind of prize would you be excited to win? Let us know!”

Animated two-way text exchange

Automate responsibly

Use chatbots and automated systems (such as Verse.ai) to easily manage conversations, but ensure they respond in a natural and human-like manner.

Leveraging safeguards and guardrails around any AI or automated system is key. The human-in-the-loop approach helps ensure that responses are authentic, and that a person can step in if the AI does not know how to respond.

At Verse, our AI is trained extensively to sound just like a human. In addition, we leverage human-in-the loop for quality assurance in every communication.

Avoid Spam Filters the Easy Way

As mentioned previously, Verse is an expert on SMS because that’s what we do. For our clients, we fully manage SMS conversations using advanced AI, with human-in-the-loop for quality assurance. 

Satisfied man texting with Verse


With Verse, benefit from SMS with customers the easy and simple way. Our expert carrier relations team has great relationships with mobile carriers, and will help to review your messaging for anything that could trigger spam filters. 

We also constantly monitor your deliverability and opt-out rates and flag any issues.In addition, we assist with SMS compliance, including A2P and TCR registration.

Verse offers:

  • A fully-managed, AI-enabled platform and a full team of human concierges for quality assurance
  • Interactive, two-way SMS conversations with customers
  • Expert help with creating scripts and screening for spam triggers
  • Constant deliverability monitoring 
  • Compliance guidance and enablement
  • Fast, effortless integration with your CRM
  • Expert guidance on messaging content and SMS best practices

Get started with an interactive, hands-off SMS strategy that converts more prospects.