Accepted phone number formats for SMS in Klaviyo

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Learn which phone number formats Klaviyo accepts when importing phone numbers for SMS marketing. 

Accepted phone number formats

You can use several different formats for phone numbers with Klaviyo. Below is a chart listing the accepted phone number formats and examples.  

Format Example without country code Example with country code
E.164 2345678901 +12345678900
2-345-678-901 +12-345-678-900
2 345 678 901 +12 345 678 900
RFC3966  tel: 2345678901  tel: +12345678900
E.123 national notation   (234) 567 8901  (+1234) 567 8900
 2345678901  +12345678900
E.123 international notation  2 345 678 901  +12 345 678 900
 234 567 8901  +1 234 567 8900

When importing phone numbers, you must include the country. The best way to do so is by adding a column labeled Country, even if you already include the country code.

The RFC3966 format comprises the prefix “tel:” followed by numbers. The numbers themselves do not need to be in a certain format.

Branded sender IDs are not accepted, but you will get one free with your SMS plan. 

Importing phone numbers

In order for consent to be applied to a phone number, we recommend including the following columns:

  • Email (if known)
  • Phone number (required)
  • Country
  • First and last names
  • Timestamp

This way, the file contains all the necessary and helpful information. Not only will consent be applied properly, but you'll avoid creating duplicate profiles.

For more details, read Upload a List of SMS Contacts

Including a country

You must indicate the country for a phone number to be accepted for SMS. You can either:

  • Include a column for the country
  • Add a country code at the beginning of the phone number

For instructions on formatting countries in CSVs, please see How to include a country for an SMS import.

With the country column
Sample CSV file for importing SMS consent into Klaviyo when there’s a country column
With the country code 
Sample CSV file for importing SMS consent into Klaviyo when there’s a country code

In other contexts, such as API calls, Klaviyo can also infer the country code based on profile information, such as a profile’s location, shipping, or billing address country.


How Klaviyo handles symbols and spaces

Klaviyo can also handle certain typos and common symbols. For instance, if a phone number contains a symbol, extra space, or letter, Klaviyo will remove this when a phone number is added to a profile. The following will all be corrected to the E.164 format as +12345678900:

  • +12/345(678)*900
  • +12()*- 345678900
  • abcde()*()++12 345 678 900
  • +1-2-3-4-5-6-7-8-9-0-0

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