ReadyCSV guides

HubSpot import error guides

Short, practical explanations of common HubSpot CSV import failures and how to catch them locally before importing.

Start with the error you are seeing

HubSpot import date format errors

Fix HubSpot date columns that use Excel serials, written-out dates, dots, or unsupported formats.

HubSpot invalid email import error

Understand INVALID_EMAIL, INVALID_DOMAIN, duplicate emails, and additional email address imports.

HubSpot lifecycle stage import error

Check lifecycle stage and lead status values before HubSpot rejects an import row.

Preflight locally before upload

ReadyCSV checks HubSpot contact CSVs in your browser before you upload them to HubSpot. Your CSV contents stay on your device: no upload, no account, no AI calls.

Use the guides to understand the import risk, then run a local preflight and review the findings before importing. ReadyCSV does not guarantee import success.

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