Import problems
Diagnose and fix common errors with CSV and XLSX imports in Nomow.
Import issues almost always come down to column mapping, file format, or deduplication expectations. The questions below cover the most common problems and how to resolve them.
The preview shows "would create" for rows I expected to merge onto existing contacts
The deduplication key is email. If the email column is not mapped — or is mapped to the wrong Nomow field — every row looks new to the importer. Return to step 3 (Map columns), confirm that your email column is mapped to the email target field (not raw.email or a custom field), and re-run the preview. Also confirm the email values in the file exactly match what is already in Nomow — extra spaces, capitalisation differences, or . vs no-. in the local part all count as different emails.
Duplicates appeared in Contacts after an import
This happens when two rows in the same file have different email addresses for the same person (for example, a personal and a work address), or when one row has no email at all and lands as a new contact regardless. Review the file, pick one canonical email per person, and use Import history & revert to revert the bad import before re-importing the corrected file.
I imported from an XLSX file and it used the wrong sheet
The wizard shows a sheet picker at step 2. If you skipped past it quickly, check which sheet name appears in the History row for that job. Revert the import, start again, and select the correct sheet at step 2.
Only some columns appear in the mapping step
The wizard reads the first non-empty row of the file as the header row. If your file has a title row above the headers, or merged cells at the top, the parser may misread the structure. Open the file, delete any rows above the true header row, save as a new CSV, and re-upload.
My import job is stuck in "Running" and the counters are not moving
A job that has not updated for more than 10 minutes is stuck. Click Cancel on the job row in the History tab, verify your file is under 50,000 rows and correctly formatted, and start a new import with the same file. The failed job remains in history for audit purposes. See Import history & revert for the full recovery steps.
A job completed but the error count is high
Click the job row in History to expand the error log, then click Download error log to get a CSV of the failing rows with the reason for each failure. Common reasons: malformed email (missing @ or domain), a value too long for the target field, or a character-encoding issue in the file. Fix the rows, save them as a new file, and import only the corrected subset.
I need to undo an import that created bad records
Open Import → History, find the job, and click Revert. Revert soft-deletes every contact and company the job created. Records that existed before the import — including any that were merged onto — are not affected. Note that merged field values on pre-existing contacts are not rolled back; correct those manually. Full details in Import history & revert.
Company fields (industry, employees, country) are blank after import
Company fields must be mapped to the company-level target fields (industry, employees, country, city), not left as raw.* values. Return to the mapping step, set those columns to the correct company targets, revert the original import, and re-import the corrected mapping.
The file upload fails immediately
Ensure the file is .csv, .xlsx, or .xls and is not larger than the workspace's plan limit. Files over roughly 25 MB are uploaded in server-side chunks — if your connection drops mid-upload, retry with a stable connection. Compressed or password-protected files are not supported; export a plain version from Excel or Google Sheets.
Next steps
For column-mapping reference, see Column mapping. For the full import workflow from upload to completion, see Import wizard.
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