Invalid sale price? Start with the affected source rows.

Keep two files and preserve the full IDs

Save untouched copies of the Merchant Center affected-products export and your source catalog. The first is an issue list, not a replacement feed. Match full IDs before editing; do not collapse several variants into a shared title or shorten an ID until unrelated products appear to match.

Compare price fields on the same variant

In each matched row, inspect price, sale_price, sale_price_effective_date and link. Open the correct variant yourself and compare its product-page and checkout prices. A different size, region or currency can make an apparently correct comparison misleading.

Google requires the sale price to be lower than the regular price, while the regular price stays in price. Use a number with an ISO currency code and keep the submitted sale price consistent with the landing page and checkout. Google: Sale price specification.

Fictional example: a regular 80.00 USD with a sale of 64.00 USD is internally plausible. It is not proof of correctness: the same variant must actually be offered at that sale price.

Check when the sale starts and ends

If you supply a sale window, use the documented ISO 8601 start/end format and an explicit time zone. Google interprets an omitted time zone as UTC. Compare the window with your store’s promotion schedule instead of assuming your local clock is the feed’s clock. Google: Sale price effective date.

Fix the authoritative source, then check again

Make a small, verified correction in the source that normally supplies those products. Keep a before/after copy. Let your usual feed process send the change, then inspect Merchant Center’s processing and issue results. Re-export remaining affected IDs if necessary; do not assume a successful local check means Google has accepted the update.