StriveFormats
CSV Fixer
Google Merchant CenterSKUs & IDsImport blocker

Duplicate id

Two or more rows use the same id.

What is this issue?

Two or more rows use the same id.

Affected field:id
Import blocker: your file will fail to import until this is resolved.

What it looks like in your file

In your file
id
2MUG-01
3MUG-01
After the fix
id
2MUG-01
3MUG-02

Upload your CSV to check for this issue and export a clean file.

Fix now

Why Google Merchant Center rejects this

Google identifies each product by its id. With duplicates, one row overwrites the other and data from the wrong product can show.

Fix in StriveFormats

StriveFormats highlights all rows with duplicate identifiers so you can see exactly which rows conflict.

Open CSV FixerView templateGoogle Merchant Center Fixer guide

Fix in Excel

  1. 1In Excel, click the column letter for the id column.
  2. 2Go to Home > Conditional Formatting > Highlight Cell Rules > Duplicate Values. Duplicate cells will be highlighted in red.
  3. 3For each highlighted pair, decide which row to keep. Either delete the duplicate row, or change its identifier to something unique.
  4. 4After resolving all duplicates, clear the conditional formatting: Home > Conditional Formatting > Clear Rules > Clear Rules from Selected Cells.
  5. 5Save as Text (Tab delimited) (*.txt).

Fix in Google Sheets

  1. 1In Google Sheets, click the column letter for the id column.
  2. 2Go to Format > Conditional formatting. Set 'Format rules' to 'Custom formula is' and enter =COUNTIF($A:$A,A1)>1, replacing A with your column letter.
  3. 3Set a highlight color (e.g., red fill) and click Done. Duplicate values will be highlighted.
  4. 4For each highlighted cell, either delete the duplicate row or assign it a unique identifier.
  5. 5Remove the conditional formatting rule when done.
  6. 6Go to File > Download > Tab Separated Values (.tsv), then rename the file to end in .txt.

Prevent it next time

  1. ✓Define a clear naming convention for SKUs and identifiers before adding products.
  2. ✓Use a prefix system (e.g., SHIRTS-001) to keep identifiers organized and unique.
  3. ✓Before exporting, sort by the identifier column and scan for consecutive identical values.
  4. ✓Understand the difference between intentional duplicate parent identifiers (variant grouping) and accidental duplicates.
  5. ✓Run StriveFormats before every import to catch duplicates early.

How StriveFormats detects this

StriveFormats builds a frequency map of all values in the id column as it parses the file. Any value that appears more than once is flagged on every row where it occurs.

►Technical detail
Google Merchant Center uses certain column values (like Handle, SKU, or Listing ID) as unique identifiers to decide whether to create a new record or update an existing one. When the same identifier appears more than once in the file, the importer's behavior depends on the platform: Shopify merges rows with the same Handle into one product (intentional for variants), while duplicate SKUs on separate products or duplicate Listing IDs on Etsy cause unexpected overwrites. Understanding whether a duplicate is intentional (variant grouping) or accidental is key to resolving this issue correctly.