Guide to Configuring SMS and MMS Messages

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After you’ve set up SMS messaging in your campaigns and flows, you can start building out your SMS messages. This article will run through creating an SMS message in Klaviyo, configuring the content, and some best practices for text messages.

Check out our guide to Getting Started with SMS for step-by-step instructions on how to start using SMS. 

Adding an SMS Message

Before you start creating and sending SMS messages in Klaviyo, you need to enable SMS on your account. For instructions on how to do so, read Set Up SMS.

Create SMS content by clicking a specific flow or campaign name. For SMS campaigns, choose the name and recipients and then navigate to the Content step.


For flows, drag in an SMS component and select Configure Content.


Building Out Your SMS Message

All of your SMS messages should contain:

  • A clear indication of who the SMS is from
  • Relevant, short, value-adding content
  • Opt-out language (which cannot be toggled off as not including STOP or similar text will cause your messages to be heavily filtered)

You can also use emojis, GIFs, and images in your texts. For more details on using graphics, check out MMS Image and GIF Best Practices.

To start, you should either toggle on the Organization Prefix option within the SMS builder or indicate in your messaging who is sending the text. You don’t need a long, drawn-out message, but mention your brand within the first few words of your SMS to tell your recipients where the message is coming from.


Next, you only have a matter of seconds to make an impression on your recipients, so keep your message short. SMS messages are limited to 160 text characters or 70 special characters. MMS messages are able to have up 1600 characters. 

That being said, in general, try to write in full sentences and don’t use abbreviations. While it may be tempting to use texting abbreviations to keep your text short, your abbreviations may not be apparent to the recipient and could make your brand appear unprofessional. If you have a very specific brand tone and a customer base that you feel confident will understand your abbreviations, it's fine to use them sparingly. 


Lastly, Klaviyo includes opt-out language in all SMS and MMS messages. This ensures that you won’t receive spam complaints, potentially costing you fees. For more information about SMS and spam, head to our article on US SMS Compliance Laws.


You can personalize your message by using any of the properties in the Add Property dropdown, which shows all of the template variables available in Klaviyo. Using this, you can, for example, address the recipient by their first name, if it's known. If it's not, you can use a generic term, such as "friend."


As you begin creating your message, you'll see how the message will look once it's delivered to a certain recipient. This recipient is shown in the card in the upper right-hand corner. For list- and segment-triggered flows, you can search for any profile in your account or select from the 10 most recent profiles added to the list or segment.  


Date property-based flows are similar except that they will only show a profile that has the date property that triggers the flow.

When it comes to metric-triggered flows, the card will show the 10 most recent events for the flow's trigger along with the associated event variables. Like with the profile properties, you can simply click on one of the variables to copy it to your clipboard. 


After you finish with the message content, you can add an image or GIF to send an MMS. Simply click the Add Image/GIF button under Message on the left-hand side.


Best Practices

SMS messaging is a great point of contact with your customers, allowing you to remain at the front of their minds. When you’re configuring your message in Klaviyo, it’s important that you adhere to the following tips to get the most out of your SMS marketing.


First, you need to have the proper permission to text someone. Make sure you’ve obtained a customer’s phone number from a legal source (i.e., signup form, in-person event, opt-in on a checkout page). Klaviyo will never send an SMS to a profile that doesn’t have consent. For more information head to the article on How to Collect SMS Consent.


It’s best practice to text a single SMS recipient anywhere from two to six times a month. Like your emails, you’ll want to make sure that you stick to a regular schedule when sending out your SMS messages. Additionally, create a customer journey for someone who signs up for your welcome series or abandons a cart, and figure out how often you’re communicating with that person. You don’t want to communicate too little or too much with a customer. Anywhere between two and six messages a month is a good cadence to start.

Time of Day

As you send out your texts, you’ll want to send them between 8 am and 8 pm in the recipient's local time. Most likely, sending an SMS too early in the morning or too late at night will lead to fewer conversions and more people unsubscribing from communication with you.  

Test when your recipients like to hear from you. For instance, many ecommerce businesses find that sending around noon on Sunday leads to better performance. 

Content of Message

Next, when crafting your message, use personalization when you can. You can use profile and event information within your SMS messages, just as you would within an email. Head to this article on Template Tags and Variable Syntax to learn more.


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