Each purchasable variant needs its own stable item ID. A group ID links related variants, while explicit options such as size and color describe the difference between them. Keep identifiers as text so that spreadsheet software does not remove leading zeros or change long numeric values.
Within a group, use the same option dimensions for every variant and avoid two rows with the same option combination. The group ID must differ from purchasable item IDs and must not collide with another item in the feed. Duplicate or ambiguous item IDs prevent safe matching during comparison and approval carry-forward, even if the visible product titles differ.
What to do
- Assign one unique item ID to each purchasable offer or variant.
- Use a separate stable group ID for related variants.
- Populate the same option dimensions across that group.
- Resolve duplicate IDs, duplicate option combinations, and group collisions in the source.