Troubleshooting invalid format error messages

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You will learn

Learn what Invalid _ format error messages mean and how to avoid these messages when uploading a list using a CSV file. 

Table of contents

  • About mismatched data types
  • Error: Invalid consent channels
  • Error: Invalid list format
  • Error: Invalid boolean format
  • Error: Invalid number format
  • Error: Invalid email format
  • Error: Phone number formatting issues

About mismatched data types

When you import a list into Klaviyo, the field mapping page enables you to match any properties to their corresponding data type in Klaviyo. For example, Email always has a String data type; whereas, if you upload a custom property for Birthday, you will want to set the data type to Date.

Review the data types, acceptable formats, and examples below. 

  • String
    Any text, or combination of text and numbers. If you are unsure what format your data is in, choose this option. 
    • Examples:
      Hello, world
  • Numeric
    All numbers. Do not include currency symbols in numeric fields. 
    • Examples:
  • Boolean
    True or false values.
    • Examples:
  • Date
    Reference our guide to acceptable date and timestamp formats for profile and event properties to learn about accepted date formats.
    • Example:
      2014-09-01 13:34:08
  • List
    Data must be formatted as a JSON array. 
    • Examples:
  • Consent
    Data must be formatted as a JSON array of marketing channels the subscriber has consented to. Channel options are limited to email, web, sms, directmail, mobile, and push. 
    • Examples: 

For more information about what the different data types entail and which to select when importing your list, head to our guide on understanding data types.

Error: Invalid consent channels

The “consent” data type can only contain the channels a contact is subscribed to. Boolean values (true or false) are not accepted values for the “consent” data type. 

If a contact is subscribed to just one channel, a “consent” field can contain that channel’s name (e.g., “email”). 

Consent in a CSV.jpg

If a contact is subscribed to more than one channel, the “consent” field must contain a JSON array containing the channels they are subscribed to (e.g., ["sms","push","directmail"]). 

Valid channels are: 

  • email
  • web
  • sms
  • directmail
  • mobile
  • push

Error: Invalid list format

In order to use the “list” data type, your data must be formatted as a JSON array. A JSON array is always surrounded by square brackets, and each list item is surrounded by quotation marks. Every list item except the last one must be followed by a comma. 

Make sure to use straight quotes (" ") rather than curly quotes (“ ”). 

Below are properly-formatted JSON arrays: 

  • ["apples","bananas","oranges"]
  • ["apples"]

Error: Invalid boolean format

A boolean value must be either true or false. If your column of boolean values contains anything other than true or false, replace the values or upload the property as a string instead. 

Error: Invalid number format

The “number” data type accepts whole numbers (e.g., 1, 63) and floats (e.g., 1.5, 233.018). This data type does not allow any special characters, including currency symbols. 

Error: Invalid email format

Klaviyo will automatically skip email address entries that are not in a valid format. A valid email address, such as, is made up of a local part (jane), an @ symbol, and a case-insensitive domain part ( If any of these required parts are missing, we consider the email invalid. If there are erroneous spaces in the email address, we will also consider the email invalid.

You can search your CSV for invalid emails. Highlight the list of email addresses and select Data > Filter. Then, filter out any email addresses that do not contain symbols like "@" or "." Fix or remove these invalid emails before re-attempting your import.

If your email addresses are all formatted correctly, but you still receive this error message, check for any line breaks within cells and remove them. Line breaks within a cell in your CSV will be interpreted as new rows in the upload, causing misalignment between the data and your headings.

Error: Phone number formatting issues

Phone numbers must include a country code or a separate column indicating their country, and must follow an accepted phone number format. Learn how to properly format and upload phone numbers

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