Duplicate headers
Repair duplicate headers in CSV files
Make duplicate header names unique without losing readability, so import mapping stays predictable.
What this problem usually means
Duplicate headers can make an import file look fine at a glance while still breaking field mapping in the destination system. If two or more columns share the same name, many importers cannot tell which one should map to the intended field.
Why it happens
- The source export includes two fields with similar labels, and both were shortened to the same header name.
- A spreadsheet edit duplicated or copied a column without renaming the header.
- A merge process combined datasets and produced repeated column labels.
What ImportFix checks
- Repeated header names after trimming and normalization
- Whether the file also has row-shape or delimiter problems
- How many duplicate headers were found
- What the repaired header names look like before export
Common repairs
Rename duplicate headers into unique, readable names
Keep the original order so mapping stays easier to review
Clean up related issues like blank columns or whitespace
Export a clearer CSV for the destination importer
When to review manually
Renaming duplicate headers fixes the structural mapping problem, but you should still confirm that each resulting column corresponds to the right business field before importing.
Related guides
Keep exploring the most common import problems, or jump into the repair workspace directly.