Google Ads Offline Conversion Upload Errors: How to Fix Your CSV
Offline conversion import errors are often caused by simple CSV-level problems. Use this guide to spot the most common issues before uploading your file to Google Ads.
Missing headers
Google Ads offline conversion uploads depend on recognizable columns such as Google Click ID, Conversion Name, Conversion Time, Conversion Value, and Conversion Currency. If headers are duplicated, blank, or named inconsistently, rows can fail before Google Ads can interpret the file.
Invalid conversion time
Conversion Time should include a parseable date and time. A date-only value can be ambiguous, and a future timestamp is almost always wrong. Include a timezone such as +08:00 where possible.
Old click IDs
Very old click-based conversions are risky. If the conversion time is more than 90 days old, verify that the import window and business process make sense before upload.
Un-hashed user data
Enhanced Conversions for Leads often uses user-provided data such as email and phone. Plain-text user data may need to be normalized and hashed with SHA-256 before upload, depending on the workflow you use.
Duplicate conversions
Duplicate identifier + conversion name + conversion time combinations can cause confusion or duplicate import attempts. Use an Order ID where appropriate and remove accidental duplicates before uploading.
What a local checker cannot verify
A browser checker can catch CSV-level issues, but it cannot confirm conversion action ownership, account permissions, whether a click belongs to the account, or final attribution inside Google Ads.
Check your CSV before upload
Use the free browser-local checker to find missing fields, invalid times, suspicious identifiers, user data issues, and duplicate rows before import.
Open the checker