Product identity reference

Shopify product and variant identifier reference

Scope Shopify IDs, handles, SKUs, barcodes, GTINs, MPNs, URLs, and schema IDs without treating them as interchangeable.

Identifier	Scope	Public use	Main failure
product ID	Shopify product record	internal/API relation	exposed as SKU
variant ID	sellable variant	variant URL/cart relation	lost when first variant is assumed
handle	URL component	canonical routing	changes without redirect
SKU	merchant inventory item	fulfilment and Product offer	reused across distinct variants
barcode/GTIN	assigned trade item	cross-system identity	invented or parent value copied
MPN	manufacturer part	manufacturer identity	replaced by Shopify ID
schema `@id`	entity graph node	connects Product/Offer/Review	duplicate owners create unrelated IDs

Rhode’s observed 4.2 oz and 1.7 oz offers used one SKU, so the correct scanner state is needs_review, not an automatic accusation. HexClad’s real SKU remained useful even though Default Title polluted the name.

Variant URL check

curl -sSIL 'https://example.com/products/item?variant=123'

The page should select variant 123, expose its price/stock/SKU, and retain an intentional parent canonical strategy.

Rules

never invent identifiers
preserve leading zeros in SKUs/barcodes
attach variant identifiers to variant offers
redirect changed handles directly
keep @id stable and connected
report missing as unknown when the business does not maintain the field

Related guide: Add missing identifiers.