What is an item group ID in Merchant Center?
WeAdU · Updated 5 October 2026
The item group id attribute [item_group_id] groups, in Merchant Center, the variants of one product. Only one detail sets the variants apart: colour, size, memory or screen.
What does it not replace?
It replaces neither the [id] identifier, nor the GTIN, nor the MPN. It groups variants, and it does not name a brand.
Which figures appear on the homepage?
Exact homepage text.
| Block | Exact text |
|---|---|
| Clients | 70% of clients see a higher ROAS after we restructure their accounts |
| Scope | 14 of 20 clients, over 12 months |
| Spend | $32M+ ad spend managed |
| Sales | $241M+ in sales generated |
| Tracking | $132M+ tracked in Google Ads |
| Conversions | 5.3M+ conversions |
| Duration | 24+ years (2002) |
When does the help require it?
According to Google's Merchant Center help, the attribute is required for variants of free listings, and for variants of Shopping ads that target Brazil, France, Germany, Japan, the United Kingdom or the United States. All variants of one product share the same value, and each group has its own. Changing the case does not create a distinct group: Google reads both spellings as one value. Do not reuse a value for another product. The title [item_group_title] stays the same. The option [variant_option] names the difference. Also send, when they apply, colour, pattern, material, age group, gender and size, in addition to [variant_option]. If the product page lets the shopper choose colour or size, send all of those versions with the same item group id. The title, the option, the colour, the price, the availability and the image must match what the page shows. If these conditions are not met, Google disapproves the product.
When should the attribute stay empty?
If the product is not a variant, do not fill in the attribute. A suit (jacket and trousers) or a set of accessories is not a variant group. The parent SKU is suitable as a value, but do not submit it as a separate product. Each variant keeps its own [id].
How do GTIN and brand stay separate?
Each variant keeps the manufacturer codes (GTIN, MPN) when they exist. The item group id does not replace them, and it does not replace the brand either. It has no link with Performance Max brand exclusion, which is a Google Ads setting.
What does the WeAdU audit cover?
On the weadu.com homepage: "The free audit covers Google Ads only." No Google Ads account figure.
Help pages
Google Merchant Center help pages.