How to upload a list of SMS contacts

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You will learn

Learn how to format and import a list of SMS contacts into Klaviyo. You can only import SMS consent for people in countries where Klaviyo SMS is available

Here, we discuss importing currently opted-in profiles. If you want to import profiles and indicate that they are not subscribed to SMS, check out How to bulk unsubscribe SMS contacts in Klaviyo.

Before you begin

Before you begin importing phone numbers, you must: 

Note that when importing, any landline numbers are automatically detected, and consent won't be applied to those phone numbers. 

Why these are prerequisites

If you don’t enable SMS, Klaviyo cannot add consent to your numbers. The numbers will still show as profiles in your account, but you won’t be able to send them SMS messages because consent isn’t applied. To avoid this, simply make sure you have set up SMS. To check that SMS is enabled in your account, navigate to Settings > SMS

Turn any flows triggered by the Consented to receive SMS metric (e.g., SMS welcome series) or a list (e.g., email welcome series) to manual mode before beginning the import process. Otherwise, after the import finishes, every new contact from that CSV will be added to the flow. You should also wait at least 2 hours after the import finishes to turn the flow live again. 

Klaviyo will either add consent to all imported contacts or none of them. Therefore, it’s critical to only upload a CSV where all contacts are currently subscribed to SMS. You don’t want to accidentally text someone who never subscribed or has opted out. Not only does this provide a bad customer experience, but it is also against compliance regulations and Klaviyo’s Terms of Service.

Required information for an SMS import

To upload SMS consent, the CSV must include the following for each contact: 

  • Phone number
  • Country, either in a column or as a country code

For more information on including a country, read How to indicate the country for an SMS import. This will explain how to reformat or combine (i.e., concatenate) cells so that the country is indicated properly, as in the example below. 

Indicating the country via a country code Indicating the country via a column with the country's name


Recommended information

We recommend including the following, if available: 

  • *Email address
    • If included, this should be the first column
  • Consent timestamp
  • First name
  • Last name

The consent timestamp is optional. It’s good to include if it’s available, but note that the timestamp must follow one of the accepted date/time formats

If you choose not to include the timestamp, you will need to check a box to confirm that all profiles are currently opted into SMS. 

How to import an SMS CSV 

Steps for importing a CSV with your SMS subscribers: 

  1. Navigate to the Audience > Lists & Segments tab on the left.
  2. Select the list you want to add your contacts to (e.g., SMS Subscribers).
  3. Click Manage List.
  4. Choose Import Contacts from the dropdown.
    Manage List dropdown where you can select Import Contacts
  5. Choose the CSV file you want to upload.
  6. Map each column from your CSV to an appropriate property in Klaviyo.
  7. Optional: if you want to import consent for email and you are confident everyone in the CSV is opted in, click Subscribe to Email Marketing.
  8. If there is no timestamp and you are confident the person is opted-in to SMS, click Subscribe to SMS Marketing.
    Import page when you are updating the profiles' SMS consent status
  9. Review the modal that appears.
  10. Check I acknowledge that the profiles in this import have provided explicit SMS consent to verify that you:
    • Have previously obtained SMS consent from these contacts, via another SMS platform or otherwise.
    • Are willing to accept the legal implications of texting these contacts.
      Awknowledgment that all contacts you are importing are currently subscribed to your SMS program
  11. Click Update SMS Consent.
  12. Click Review Import.
  13. On this page, check the following:
    • How many columns you are importing 
    • How many columns you are skipping from the original CSV file 
    • If SMS consent has been updated 
  14. Click Start Import when you are ready to begin.

The import process can take up to a couple of hours to complete.


Once all the numbers are imported, Klaviyo will either create a new profile or associate the data to an existing profile. For instance, if you import a phone-number-only CSV, Klaviyo will look for profiles with the same phone number, update that profile's SMS consent status, and include any other profile properties attributed to that contact. 

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