Merchant Center is the basis of any product campaign on Google. If the feed has errors, products do not appear, appear badly or are disapproved. A systematic reading of diagnostics and a simple maintenance routine avoid silent sales losses.
The essentials in a definition
Merchant Center diagnostics show product-data, account and policy problems that can disapprove products or limit ads. The most common errors are price or availability differing between feed and page, missing identifiers (such as GTIN), non-compliant images and incomplete shipping information. Follow the data specification, image rules and keep structured data consistent.
What the diagnostics are
Merchant Center checks the feed, the site and policies, and flags problems by product and at account level. There are errors that block approval, warnings that reduce performance and suggestions. Understanding the difference helps prioritise.
A disapproved product spends no budget, but it does not sell either.
Most common errors
Price or availability different from the site. Low-quality images or ones with unallowed overlaid text. Missing product identifiers (codes, brand). Unclear titles and descriptions. Missing shipping and returns information. Landing pages that do not work. Missing refund policies or contacts. Check the current official requirements.
Most come from the data source, not the feed.
Merchant Center: diagnostics and common errors
- Read diagnostics by priority
- Fix price, stock and identifiers
- Enrich titles, attributes and images
- Check weekly
Improving beyond approval
Titles with brand, type and relevant attributes. Clear descriptions. Correct categories. Good images. Complete attributes (colour, size, material). Good identifiers. Up-to-date stock and price information. Custom labels to separate margins, campaigns and seasonality.
A rich feed improves relevance and performance.
A healthy feed is the first step of any product campaign.
Maintenance routine
Check diagnostics weekly. Set up alerts. Test changes on a few products before generalising. Ensure the commerce platform updates the feed frequently. Document transformation rules. Review before peak seasons and when the catalogue changes.
Continuous maintenance avoids scares.
Decision table
| Frequent error | Usual cause | Fix |
|---|---|---|
| Price differs on page | Outdated feed or promotions not reflected | Update frequently or use automatic rules |
| Missing GTIN or brand | Incomplete data | Complete or indicate when they do not exist |
| Non-compliant image | Watermark, text or low quality | Replace with a suitable image |
| Missing shipping or returns information | Incomplete configuration | Complete in the account and on the site |
Common mistakes to avoid
- Ignoring warnings. They worsen and become disapprovals.
- Fixing only the feed. The page must match too.
- Not monitoring. Problems return with catalogue changes.
How to measure the result
Track the number of approved, disapproved and warned products, and average resolution time.
Limits and exceptions
Specifications and policies change; always confirm current documentation. Some problems depend on the commerce platform and require technical support. Approval guarantees neither delivery nor performance.
Illustrative example
Illustrative example: a store sees many products disapproved for price mismatch. It finds that promotions enter the site but the feed updates only once a day. It switches to more frequent updates, validates price markup and tracks diagnostics weekly. Disapprovals fall and ads are delivered again.
In practice: checkpoints
Create a weekly diagnostics routine with an owner and a log of corrections made and their effect. Compare feed attributes with the product pages, review disapproved items first, then warnings that may become errors, and check shipping and returns settings after every policy change. Use feed rules sparingly and document them, since rules hide problems at the source. Plan catalogue updates with the commerce team, and test a sample of products on the live site after imports.
Frequently asked questions
How often should I check diagnostics?
Weekly, and before peak seasons.
What is the most frequent error?
Price or availability different from the site.
Do titles matter?
A lot. They influence relevance and clicks.
How often should I review diagnostics?
Weekly, and after catalogue changes.
Can I automate fixes?
In part, with feed rules, but always confirm the results.
In Merchant Center, fix the source of errors (price, identifiers, images, shipping), keep feed and page matching and monitor diagnostics regularly.
Sources and recommended reading
- Merchant Center: product data specification
- Merchant Center: image_link attribute
- Google Search Central: product structured data
Last editorial review: October 2026. Informational content; always confirm current conditions in the official sources before deciding.