Troubleshooting invalid format error messages

You will learn

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

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 Text 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, consent fields, acceptable formats, and examples below.

• Text
  Any text, or combination of text and numbers. If you are unsure what format your data is in, choose this option.
  • Examples:
    email@example.com
    Hello, world
    $5.00
• Number
  Whole numbers and decimals. Do not include currency symbols or thousands separators in number fields.
  • Examples:
    2
    5.0031
    130.0
• Boolean
  True or false values.
  • Examples:
    true
    false
• 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:
    ["apples","bananas","oranges"]
    ["apples"]
• Consent fields
  Map each consent column to the appropriate Klaviyo property, such as Email Marketing Consent, SMS Marketing Consent, or SMS Transactional Consent. These fields use the Text data type. Use Subscribe, Never Subscribed, or Unsubscribed as the value in each cell.

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 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 text item is surrounded by double quotation marks. Every list item except the last one must be followed by a comma. Keep the entire array in one cell, even if it contains only 1 item.

Below are properly-formatted JSON arrays:

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

Error: invalid boolean format

Use true or false for Boolean values. Klaviyo also accepts 1, t, yes, and y for true, and 0, f, no, and n for false. These values are not case-sensitive. Replace unrecognized values, or select Text as the data type if you want to store them as text.

Error: invalid number format

The Number data type accepts whole numbers (e.g., 1, 63) and decimal numbers (e.g., 1.5, 233.018). Negative values such as -5 are also accepted. Remove currency symbols and thousands separators (e.g., use 1000 instead of 1,000).

Error: invalid email format

Klaviyo automatically skips email address entries that are not in a valid format. A valid email address, such as jane@example.com, is made up of a local part (jane), an @ symbol, and a case-insensitive domain part (example.com). If any of these required parts are missing, we consider the email invalid. Spaces within an email address make it invalid; leading and trailing spaces are removed during import.

Use your spreadsheet’s filters to look for email addresses missing an "@" symbol or a "." in the domain. This is an initial check, not a complete validation of the addresses. Fix or remove invalid emails before re-attempting your import.

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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 can cause parsing errors or misalignment between the data and your headings.

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Error: phone number formatting issues

Phone numbers must start with a + and country code (e.g., +1), or have a separate Country column indicating their country, and must follow an accepted phone number format. Learn how to properly format and upload phone numbers.

Correct errors and retry your import

Before reimporting, review the prerequisites in How to import subscribers to a list.

1. Open the list you imported to and select the Imports tab.
2. If Download error file is shown for the completed import, click it and review the Errors column. If the button is not shown, check your original CSV using the format guidance above.
3. Correct the affected values in your CSV using the guidance above. If you are reusing the downloaded error file, remove the Errors and Warnings columns before uploading it.
4. Click Upload new file and upload the corrected CSV.
5. Review the column mappings and data types, complete any consent prompts using your contacts’ actual consent status, then click Import.

When the import finishes, check the Imports tab again to confirm the result and see whether any rows still need attention.

Additional resources