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.

The RFC3966-style format starts with tel: followed by the phone number. Include the country calling code or supply the country in a separate column, as described below.

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

Importing phone numbers

When preparing your CSV for an SMS import, include the following contact details and any consent information you have:

• Email (if known)
• Phone number (required)
• Country (required if phone numbers do not include a country calling code)
• First name (optional)
• Last name (optional)
• SMS Marketing Consent (if importing consent statuses): Subscribe, Unsubscribed, or Never Subscribed
• SMS Marketing Consent Timestamp (optional, if known)

Including an email address, when known, helps Klaviyo match a contact to an existing profile. Contact details alone do not establish SMS consent. To import consent, map the appropriate consent fields from your CSV or confirm consent during import. Only subscribe contacts who have explicitly opted in to SMS.

For instructions on mapping fields, confirming consent, and completing your import, 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 labeled Country with the country for each contact
• Add + and the country calling code at the beginning of each phone number (e.g., +12345678900)
  • In Google Sheets or Excel, you can enter an apostrophe before the plus sign (e.g., '+12345678900) to keep the phone number as text. Check that the exported CSV retains the plus sign and all digits.

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

With the country column

With the country code

How Klaviyo handles symbols and spaces

Klaviyo can normalize certain extra spaces, punctuation, and other characters when it can parse a phone number. This does not correct wrong or missing digits, so check your source data before importing. The following will all be converted to 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

Additional resources