From my testing, MPN values entered there seem to sync to Merchant Center only for products without variants. For products that have variants, the MPN values appear to be saved in Shopify, but they don’t seem to arrive in Merchant Center.
After installing the Google & YouTube app, I can also see several Google related variant metafields in Shopify, for example:
you are using the free sales channel app right? as far as my understanding goes, that app has a problem in showing the specific (unique) for each variant when it comes to the MPN attribute field. and i am not sure if google ever resolved it.
there are several ways to fix it like you can use a supplemental product feed (which is useful only for partial data as is your case) or go with another shopify google shopping app like nabu for google shopping feed.
also, i hope that you are submitting the correct MPN value which actually belongs to the product.
and your other two questions - no, the bulk editor MPN is not stored separately, it writes into those same google variant metafields you listed. the metafields shopify’s CSV doc says the channel ignores are the older legacy google namespace ones, these are different.
so the app does read its own metafields, it just fails to pass the variant level values into the feed.
I have not used the google and youtube app for years, so I don’t know if it has ever been updated or fixed. As you are having issues, my guess is that Google is not planning to fix this.
Honestly the app is not great, it has many more other bugs, and makes decisions that are actually against there own policy.
If you want to continue to use this app, the only way is to either manually edit the products in GMC product editor, or use a supplemental feed. Both a bit silly and time consuming.
However, you need to remember that if you have no barcodes, do not submit the mpn value. Only submit the MPN value if you have brand + gtin, don’t only submit brand + mpn.
Hi @sebastian.s, I would separate this into two checks: where the value is stored in Shopify, and whether it is being submitted at the variant item level in Merchant Center.
For variant products, the important thing is to check one affected variant in Merchant Center and compare its item ID, brand, GTIN, MPN, and product source. If the MPN exists in Shopify but the exact variant item in GMC has a blank MPN, then it is likely a feed/app submission issue rather than a product data entry issue.
I would also be careful not to submit MPN as a substitute for GTIN unless that is actually the manufacturer part number for the product. For branded products, Google usually prefers the real GTIN when available.
A practical workaround is to test one product with 2-3 variants first, confirm what reaches GMC, and only then bulk-edit the rest. Otherwise it is very easy to update thousands of values in Shopify without knowing whether the feed source is actually sending them.
I know this thread is a bit old, but I came across it and I’m curious if anyone has found a definitive solution or if we’re still using workarounds. Has Shopify released any updates or is the supplemental feed still the best bet for getting those MPNs into GMC for variant products? Would love to hear any new insights!
If support says variant MPNs are supported, I’d ask them to point to the exact feed item where the value is supposed to appear.
The source of truth is not the Shopify field — it’s the final item in Merchant Center. For variant products, check the variant item ID / item_group_id and confirm whether each child variant has its own MPN in the feed output.
If the value is saved in Shopify but missing in GMC, I’d use a supplemental feed keyed to the exact variant item IDs until the channel app proves it’s fixed. Way safer than repeatedly bulk-editing product data and hoping the next sync behaves.
