Fix “invalid number format” before a Klaviyo import

A value can look like a number to a person while still failing a numeric property check because it contains a currency symbol, unit or other text.

What Klaviyo expects

Number properties accept numeric values rather than display-formatted strings. Values such as €19.99, 12 kg or other text-decorated numbers should not be mapped directly as Number.

What ReadyRows checks

ReadyRows infers likely numeric custom columns from their headers and sampled values, then flags entries that contain non-numeric content. Ambiguous values are left unchanged for review rather than rewritten.

Avoid locale mistakes

Commas and periods can have different meanings across locales. Do not automatically swap separators unless you know whether the source means a decimal separator or a thousands separator.

Official reference

Klaviyo documents the relevant import rule in its invalid format troubleshooting guide.

ReadyRows is an independent tool and is not affiliated with Klaviyo. Import rules can change; confirm account-specific behavior in the platform's official documentation.