Upload a Shopify customer export CSV. Find duplicate emails, invalid email formats, missing names, phone number issues, province and country code errors, and encoding problems before re-import or migration.
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The checker finds these automatically and tells you exactly which row and cell to fix.
Duplicate email addresses
Shopify uses email as the unique customer key. Duplicates cause silent merges on import and corrupt customer records.
Invalid email format
Malformed emails cause Shopify to silently skip or reject customer rows during import.
Province and country codes
Shopify expects ISO 2-letter codes. Wrong values break address lookup, tax rules, and shipping zones.
Phone and consent fields
Non-standard phone numbers and invalid marketing consent values cause SMS and notification failures.
Shopify customer imports fail silently when emails are duplicated, malformed, or missing. Province Code must be a 2-3 letter ISO subdivision code, Country Code must follow ISO 3166-1 alpha-2, and marketing consent fields must be TRUE or FALSE. This checker scans every row for those problems and auto-fixes safe formatting issues so your next import succeeds.
Validates email format on every row and flags any address that appears more than once, since Shopify will silently merge those customers.
Flags Province Code and Country Code values that do not match the ISO 2-letter formats Shopify expects for tax and shipping rules.
Auto-fix preview
Normalize email casing, fix province and country code capitalisation, and clean smart quotes. Download a corrected CSV ready for Shopify import.
Common questions about validating and fixing Shopify customer CSV files.
Shopify uses email as the primary customer identifier. Importing a CSV with duplicate emails will update the existing customer record rather than creating a new one. If you intended separate records, resolve the duplicates before import.
Shopify accepts E.164 format (e.g. +61412345678) for phone numbers. Numbers without a country code prefix may be accepted but can cause issues with SMS marketing and order notifications in multi-region stores.
Province Code should be a 2-3 letter ISO 3166-2 subdivision code such as NSW for New South Wales, CA for California, or ON for Ontario. The full province name belongs in the Province column, not Province Code.
Yes. Upload any CSV that has Email, First Name, and Last Name columns. The checker validates the fields it can recognise and flags problems without requiring a perfectly formatted Shopify export.