Supplemental feed ID matcher

See which supplemental IDs miss the primary feed.

Join a supplemental CSV or Google Sheets export to the primary source feed, find IDs that do not match, and locate every matching source row without connecting your store.

01

Export both sides of the join

Download the primary product source as CSV or TSV. Export the supplemental Google Sheet or file as CSV without changing its product ID values.

02

Audit the primary source

Open the primary feed in FeedPatch. It detects common ID headers such as id, item_id, offer_id, product_id, and sku.

03

Add the supplemental CSV

Use the ID-list slot for the supplemental export. An issue-description column is optional; the matcher only needs a recognizable product ID column.

04

Review unmatched IDs

Each unmatched row is an ID that was not present in the supplied primary file. Check prefixes, variant-vs-product IDs, whitespace, case, and whether the export came from the right source version.

05

Confirm Merchant Center settings

Google says supplemental product IDs should exactly match the primary source. Also verify the selected primary source, feed label, and language in Merchant Center.

06

Fix the source and upload once

Correct the spreadsheet or source integration, export a fresh copy, and run the match again before submitting it to Merchant Center.

Diagnose before editing

Prove whether the join fails before changing campaign rules.

A high unmatched count points to an ID or source-version mismatch. A complete match means the problem is more likely in source selection, feed label, language, attribute rules, or another Merchant Center setting that FeedPatch cannot inspect.

Run the local ID join

Optional repair export

Compare IDs free. Upgrade only for the corrected full-feed export.

The match map remains free. Pro is for safe normalizations and downloading the complete corrected primary feed.

$79USD
per year
  • Free matched and unmatched ID map
  • Full-feed safe normalization export
  • Source feeds up to 100 MB
  • 14-day refund policy
Secure checkout by Paddle · No per-product fees

Frequently asked

Before re-uploading the supplemental source.

Can a supplemental source add new products?

No. Google describes supplemental sources as a way to add or update attributes on products already present in a primary source; the product IDs are used to match them.

Does the supplemental CSV need an issue column?

No. FeedPatch can join a plain ID list to the primary source. If another column contains notes, it will include recognized issue text when available.

Are IDs case-sensitive?

Merchant Center product IDs are case-sensitive, but Google warns against using casing alone to make IDs unique because it can cause matching confusion. Compare the exact exported values.

What leaves my browser?

The product files do not. FeedPatch records only aggregate product-action counters and broad traffic-source categories, never catalog rows or product IDs.

Official references

Use Google's live data-source rules as the final authority.

Create a product data sourceGoogle's primary and supplemental source setup, including exact ID matching.ID [id] specificationUnique, stable ID requirements and casing guidance.

Checked against Google Merchant Center Help on August 26, 2026. FeedPatch is an independent tool and is not affiliated with Google.