Duplicates in a CRM (several separate records for the same person or company) almost always show up the same way: a customer gets in touch through a different channel than usual (calling instead of emailing, or filling in a form with a slight variation of their name or email), and the system, not recognising them as the same contact, creates a new record instead of updating the existing one. Over time, with no cleanup process, the database piles up dozens or hundreds of these duplicates.
Why this is more serious than it sounds
Beyond looking messy, duplicates create real business problems: a sales rep can contact the same customer twice without knowing it, creating an impression of disorganisation. Purchase or interaction history gets split across several records, giving an incomplete and misleading picture of the real relationship with that customer. And any segmentation or marketing campaign based on that data risks counting the same customer multiple times, distorting the metrics used to make decisions.
How to spot them
Most modern CRMs include automatic duplicate-detection tools, which compare key fields (email, phone, first and last name) and suggest merges when they find likely matches. When that feature doesn't exist or isn't enough, exporting the database and checking for email or phone matches in a spreadsheet, though less elegant, remains a reliable method for a one-off cleanup.
How to merge them without losing information
When merging two duplicate records, the general rule is to keep the full history of both (every interaction, note and recorded purchase), not simply delete one and keep the other. Most CRMs with a merge feature do this automatically, but it's worth manually reviewing the result on important merges, to make sure no relevant data was lost in the process.
How to prevent it happening again
Setting up the CRM to validate before creating a new record (checking whether a contact with the same email or phone already exists) drastically reduces new duplicates appearing. It also helps to set a clear internal rule for how contact information gets entered (same phone format, same criteria for compound names) so two people on the team don't enter the same data in different ways the system doesn't recognise as identical.
Frequently asked questions
How often should I review duplicates in the CRM?
It depends on how many new contacts you handle, but a quarterly review is usually enough for most small and medium businesses, keeping the problem from piling up to the point of becoming hard to manage.
Can I fully automate merging duplicates?
It's possible for very clear matches (exact same email), but ambiguous cases (similar names with different contact details) should be reviewed manually, because an incorrect automatic merge can mix up the history of two different customers.
What do I do if two duplicate records have contradictory purchase histories?
Keep both histories within the merged record rather than discarding one, and if there's genuine doubt about whether it's the same person, it's better to leave the records separate until confirmed than risk mixing data from two different customers.