Shopify customer CSV fields, consent, and duplicate risks

What this guide explains

Learn which customer CSV fields need review before running a Shopify customer cleanup workflow.

• Email validity and duplicate email rows should be reviewed before name or phone formatting.
• Consent values should come from explicit source data; blanks should become review items instead of guessed permissions.
• A clean customer CSV and an issue report are more useful than silently dropping questionable rows.

Preserve identity while normalizing format

Trimming spaces and lowercasing email domains can make matching more reliable, but merging two customer rows is a business decision. Compare names, addresses, order references, and source systems before deciding that repeated emails represent one person. Keep row numbers so every cleanup can be traced back.

• Do not manufacture placeholder emails for rows that lack an address.
• Review shared household or role-based addresses before deduplication.
• Keep the original export as an audit and rollback source.

Keep consent evidence separate from contact validity

A syntactically valid email address says nothing about permission to market to that person. Normalize only explicit source consent values and leave blanks or unknown labels visible. Import and marketing rules can vary by jurisdiction and account setup, so use the cleaned file as preparation rather than legal approval.

• Do not convert a blank consent field to subscribed.
• Retain the source and date of consent outside the formatting tool.
• Test a representative subset before importing the full customer list.

Sources and further reading

• Shopify Help Center: CSV files — Official customer CSV, encoding, editing, and import guidance.