If the same customer shows up several times in Brevo, work through these checks. Most duplicates come from mismatched email addresses or phone-only records.
Quick check Brevo uses email as the unique identifier. Two records with different email spellings, or a record with only a phone number, are treated as separate contacts even if they are the same person.
Step 1: Identify Why Duplicates Happen
| Cause | Example | Result |
|---|---|---|
| Different email spellings | [email protected] vs [email protected] | Two contacts |
| Guest checkout then account | Same person, two Shopify customer records | Two contacts |
| Phone-only record | SMS opt-in with no email captured | Separate contact |
| Manual import overlap | A CSV imported alongside Tajo sync | Duplicated entries |
| Case or whitespace | [email protected] vs [email protected] | Usually merged, sometimes not |
Step 2: Confirm Tajo’s Matching Behavior
Tajo deduplicates on email before sending to Brevo. It cannot merge two records that genuinely have different email addresses, because it cannot safely assume they are the same person.
Check Tajo > Settings > Sync > Duplicate handling and enable Strict duplicate prevention. This normalizes case and trims whitespace before matching, removing the most common near-duplicate.
Step 3: Merge Existing Duplicates in Brevo
- In Brevo > Contacts, open the Duplicate contacts tool.
- Review the suggested pairs.
- Choose the master record. Prefer the one with the richest order history and valid consent.
- Merge. Brevo combines attributes and history into the master.
Tip Merge in Brevo, not Shopify. Merging Shopify customer records can rewrite order associations. Let Tajo keep syncing and resolve duplicates on the Brevo side where email is the key.
Step 4: Handle Phone-Only Duplicates
A contact captured by SMS opt-in with no email cannot be matched to an email-based contact automatically.
- Encourage email capture at SMS opt-in so future records can be linked.
- For existing phone-only records, manually merge in Brevo if you can confirm the same person.
Step 5: Prevent Future Duplicates
- Keep Strict duplicate prevention enabled in Tajo.
- Avoid manual CSV imports into the same list Tajo manages. If you must import, dedupe the file against Brevo first.
- In Shopify, encourage account creation so repeat buyers reuse one customer record instead of repeated guest checkouts.
- For multiple stores, remember one email is one Brevo contact across all stores by design; segment by
store_idrather than expecting separate records.
Step 6: Verify the Cleanup
- After merging, place a test order with an existing customer’s exact email.
- Confirm in Tajo > Sync Status the record updates the existing contact rather than creating a new one.
- Spot-check the merged contact in Brevo for intact order history and correct consent.
When to Contact Support
Reach out with specifics if:
- Duplicates keep appearing for the same exact email after enabling strict prevention.
- A merge in Brevo is repeatedly re-split by sync.
- You see thousands of duplicates suggesting a misconfigured import.
Include the affected email addresses and a screenshot of the Tajo duplicate handling settings.
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Get Help
- Live Chat: available in the Tajo dashboard (bottom right)
- Email Support: [email protected]
- Documentation: docs.tajo.io