How to diagnose repeated source product IDs

Repeated IDs can originate before the feed is generated, especially when several exports or source systems are combined. Trace the collision to its source rather than renaming final rows randomly.

Reviewed October 4, 2026 · Independent guidance · Static feed check with contextual limitations

What does this issue mean?

A combined catalog needs stable unique offer IDs across all contributing sources. Two suppliers can legitimately use the same local stock reference, but those references collide if exported unchanged into one Merchant Center source. The issue differs from duplicate rows accidentally appended within a single generator.

Why this happens

Inspect source provenance, variation references and feed merge rules. Prefixing identifiers may be appropriate when deliberately designed, but changing an established ID can affect historical associations. A product barcode does not automatically solve the collision because manufacturer identity and merchant offer identity serve different roles.

How to diagnose and fix it

1. Identify the contributing source for each record that shares an exported ID.
2. Determine whether the records represent the same offer, separate supplier inventory or distinct variants.
3. Design a consistent stable source-ID mapping, test it on a sample and assess existing integration dependencies.
4. Rebuild the merged feed and confirm that IDs are unique across the entire output, not just within each source file.

Before and after example

The examples are illustrative. Replace them with verified information for your own offer; copying an example identifier, amount or URL would introduce incorrect data.

Before

Supplier A id=101
Supplier B id=101

After review

Stable source mapping: A-101 / B-101

Feed Doctor does not add prefixes or delete collisions automatically. This source-merge workflow complements the basic duplicate-ID guide, and intentional ID migrations require merchant review.

Shopify fix

Find the affected product and exact variant in your Shopify catalog, then identify which product field or Google & YouTube channel setting supplies id. If a separate feed app generates your export, inspect its mapping instead of assuming the channel settings control that file. Change verified source data, save it, and obtain a fresh export.

Compare one affected variant and one previously correct offer before making a bulk change. Do not change stable IDs just to improve a report score. If the issue involves identifiers, verify whether the connector reads barcode, brand or manufacturer reference data. If it concerns a live page or shipping account setting, a feed-column edit alone may not resolve it.

WooCommerce fix

Open the relevant product or variation and inspect the attribute consumed by your Google feed integration. Google for WooCommerce can map product attributes into feed attributes; third-party feed generators may use different mappings. Check both the stored value and the exported result, especially when parent attributes are inherited by variations.

Update the source value or mapping deliberately and regenerate the feed. Keep product identity, currency and variant relationships consistent. Avoid editing only a downloaded snapshot if a scheduled exporter will replace that change. For an account or website issue, repair the effective configuration and public offer as well as reviewing the file.

Verify the repair before submitting

Keep the original feed as a backup and compare the same affected product IDs in the regenerated file. Confirm that the expected product count remains unchanged and that no unrelated fields disappeared. If you applied a bulk rule, inspect offers outside the original affected set as a control; an overly broad mapping can fix one problem while creating another.

Run a new static scan, then separately check live product information and your Merchant Center diagnostics. File format validation cannot determine every policy, account, image or website condition. Processing and recrawling take place in Google’s systems, so a corrected file is not an immediate promise of approval. Use the actual updated diagnostics to decide whether additional investigation is required.

Frequently asked questions

Related feed issues

• How to fix duplicate product IDs in a Google feed
• How to review missing item_group_id for variants
• How to review repeated Google Shopping product titles

Official references: Google product data specification, Shopify Google & YouTube requirements, WooCommerce attribute mapping. Requirements can vary by product, country and account setup.