Klaviyo CSV: Profiles, Lists, and Event Imports

Klaviyo Lists Live and Die by Clean CSV

Shopify and ecommerce teams in the US, UK, Australia, Canada, and Europe use Klaviyo CSV uploads to seed profiles, migrate from Mailchimp, and backfill events. Bad emails, missing consent timestamps, and Excel-mangled phone fields create suppressed profiles and compliance risk — especially under GDPR/UK GDPR expectations.

Which Klaviyo CSV Job?

Pick the import type before shaping columns.

Step-by-Step: Import Profiles to a List

Most common growth-ops workflow.

• Export or build a CSV with Email as the primary identifier (unless SMS-only profiles).
• Add only properties you need; map to existing Klaviyo properties when possible.
• Include consent fields your process requires (and lawful basis documentation outside the CSV).
• Save UTF-8 CSV; verify in Online CSV Editor that emails are intact.
• In Klaviyo: Audience → import/upload to the target list.
• Map columns carefully; do not create duplicate property spellings (First_Name vs first_name chaos).
• Review the import summary for skipped rows; fix and re-upload failures only.

Email,First Name,Last Name,Country,Accepts Marketing
alex@example.com,Alex,Nguyen,US,TRUE
sam@example.co.uk,Sam,Lee,GB,TRUE

Consent, GDPR, and Marketing Flags

CSV convenience is not legal advice — but operational hygiene matters.

• Do not mark Accepts Marketing = TRUE unless your source system recorded valid consent.
• EU/UK lists: keep source and timestamp evidence in your systems of record.
• Separate transactional contacts from marketing lists when policies require it.
• Suppressions and unsubscribes must win over stale “TRUE” flags from old Shopify exports.

Emails, Phones, and Excel Damage

Identity fields are fragile in desktop Excel.

• Trim spaces; lowercase emails if that matches your identity rules.
• Reject obvious typos before upload (spaces in emails, missing @).
• Phone numbers: keep as text with country codes (+1, +44, +61, +49) — Excel drops leading +/0.
• UTF-8 for names (José, Müller, Zoë).
• German Excel semicolon files: convert to comma CSV before Klaviyo if required.

Shopify and Other Ecommerce Sources

Common US/UK/AU stacks.

• Prefer Klaviyo’s native Shopify integration for ongoing sync; use CSV for one-off backfills.
• Customer CSV from Shopify is not automatically Klaviyo-consent-correct — map thoughtfully.
• Deduplicate on email before import to reduce merge noise.
• Custom properties (VIP tier, LTV) should use stable snake_case names agreed with lifecycle marketers.

Event / Metric CSV Imports

Historical Placed Order style backfills need timestamps you trust.

• Use ISO timestamps with timezone offset when possible.
• One metric name per import convention — match existing Klaviyo metrics exactly.
• Value/currency fields: plain decimals; document currency.
• Pilot 50 events; check activity feeds on a test profile before loading years of history.

Email,Metric Name,Timestamp,Order Value,Currency
alex@example.com,Placed Order,2026-05-03T18:22:00-04:00,128.00,USD

Exports for Agencies and BI

Profile exports feed Sheets, Tableau, and agencies.

• Export the segment you mean — not “all profiles” by accident.
• Remove unnecessary PII before sending to freelancers.
• Convert to Excel only after cleaning; keep a raw CSV archive.
• Remember exports are point-in-time; integrations keep changing.

Common Mistakes

Lifecycle foot-guns.

• Uploading purchased lists without consent.
• Creating First Name and first_name as two properties.
• Importing Mailchimp exports without remapping consent status.
• Using report CSVs as profile imports.
• Mass-updating consent flags with a spreadsheet guess.

Best Practices

Treat list imports as compliance events.

• Pilot every new source system.
• Version CSVs with list name + date.
• Document property dictionary for the brand.
• Prefer native integrations for continuous sync.
• Clean identity fields in-browser before upload.

Why Use Convert CSV Online?

Convert CSV Online is free, browser-based, and requires no account for everyday conversions. Preview Klaviyo list files in the Online CSV Editor, fix encoding and delimiters, and convert to Excel for agency reviews — useful when US, UK, AU, and EU marketers share the same lifecycle stack.

Conclusion

Klaviyo CSV imports succeed when identity fields are clean, properties are consistent, and consent columns reflect reality. Use CSV for controlled backfills; use integrations for the daily sync — and pilot before you load the whole brand history.