Expert knowledge for digital decisions

How to Prevent Duplicates in CRM?

Short answer

By checking during creation, not by cleaning up afterwards. The system should warn during input if an email, phone number, or company name with location resembles an existing record. Additionally, a regular automatic search for similarities helps – duplicates still occur, just less frequently.

Why Duplicates Occur

The same person writes once with a company address, once with a private address
The company name is spelled differently: "Müller GmbH", "Mueller GmbH", "Müller Gesellschaft mbH"
Two people create the same contact simultaneously
An import runs twice

What Really Helps

Check During Creation. As soon as an email address or phone number is entered, the system checks and displays matches. This costs the user one second and prevents most cases.

Normalization. Store phone numbers in a uniform format, ignore legal form additions during comparison, standardize umlauts.

Regular Similarity Search. A run once a month that presents suspected cases for review – does not automatically merge.

Why Not Automatically Merge

Because two similar records can sometimes represent two different people. A father and son in a family business, two locations of the same chain. Automatic merging irretrievably destroys data.

Considerations When Merging

Which record leads, which is integrated
Take over history, tasks, and documents of both
Marketing consents: The more restrictive one wins
Log the process

Before Import

The most critical moment. An uncleaned import creates more duplicates in minutes than can be generated manually in months.

Key facts

Most Effective Measure: Check During Creation
Never: Automatically Merge
When Merging: The More Restrictive Consent Wins