How to fix duplicate dealership customer records

What to check before you decide

Agree on identity rules. Decide what makes two records the same person: a matching email, a matching phone number, a VIN, or a name and address together.

Decide how a household works, and what happens when a couple shares a phone number. Write the rules so a tool can follow them, and so a person can check a merge.

Decide survivorship too. When two records merge, which name, address and preferences win?

Keep the history from both. Protect consent: if either record has an opt-out, the merged record keeps it.

Fix the sources, not only the list. A cleanup that leaves the entry points open will be undone in a quarter. Require a search before a new record is created, validate phone and email at entry, and have the DMS and CRM share a customer ID.

Then keep watching. Track the duplicate rate monthly, and review a sample of automated merges by hand. A wrong merge, putting two people in one record, is worse than a duplicate.

Assign an owner. Someone in the store should own customer data quality, review the duplicate report each month and approve rule changes.

Without an owner, rules drift and the cleanup repeats. Give the owner authority to stop a lead source that floods the system with bad records.

Watch the lead sources that create the most duplicates, which are often a marketplace that sends every inquiry as a new person or a web form that does not check for an existing email, and negotiate a fix with the provider instead of cleaning up after it every month.