Catalog fundamentals: product data, offer data, and Walmart identifiers

• GTIN — the barcode number (UPC, EAN, GTIN-14, ISBN), your Product ID at setup and the match key into Walmart's catalog. Walmart validates it against GS1, the barcode registry; an unrecognized code or one licensed to another brand usually blocks the item.
• SKU — your offer identifier. Treat it as permanent: the item editor cannot rename it, and a Walmart-fulfilled (WFS) item's SKU never changes. A seller-fulfilled item takes a new SKU only through the item spec's SKU-update flag (bulk template or feed), a one-way operation that can lose data if misused, so define it from your source system first.
• Walmart Item ID — Walmart's catalog identifier, assigned when Walmart creates the catalog entry (possibly before publication, so an unpublished item may already have one), shared by every seller on the product, and the number ending the Walmart.com URL.
• WPID — another Walmart-assigned product identifier; some reports and support forms show it beside the Item ID, others ask for it instead. Lacking it, supply the Item ID.

Every item is set up against a product type, Walmart's category-specific template (the spec), from a taxonomy it revises often. The product type decides three things:

1. Required attributes — the fields a submission must carry: the universal ones (SKU, Product ID, name, brand, price, main image) plus whatever that type's spec marks required — drinkware might require capacity or material. A blank one errors the row; some are conditionally required, so read the downloaded spec rather than a memorized list.
2. Recommended attributes — fields behind search filters, browse placement, and listing quality; they do not block setup but strongly affect whether shoppers find the item.
3. Allowed variant attributes — which attributes, such as color or size, may vary within a group (Variant groups).

Category rules ride on the product type: some categories are restricted and need approval before items publish; image and naming rules differ too. The wrong product type changes the spec, the validation, and sometimes eligibility. Item setup covers filling the spec.

Product content is the shared item page: name, brand, description, key features, images, attributes, and product type. Walmart keeps one page per Item ID, assembled from what sellers contribute, so it may show another seller's content, and your update can be accepted without changing what is visible (Content maintenance).

Offer data is yours alone and never changes what the page says:

• Price — checked against Walmart's published pricing rules.
• Inventory — the quantity on your SKU.
• Shipping template — the shipping options on your offer.
• Fulfillment method — seller-fulfilled (you or a logistics provider you hire ship the order) or Walmart Fulfillment Services (WFS) (Walmart does). Switching is a separate conversion flow outside this track.
• Offer status — active or retired.

The Buy Box — the default offer when several sellers share an item — is won on the offer, not content: Walmart does not publish the formula, but price, shipping speed, availability, and seller performance are the levers. Better content wins the page, not the Buy Box.

Seller Center moves and renames pages, so here is what each area does, with the labels most accounts show.

• Items / Catalog (often "Manage Items") — every SKU with its published or unpublished status, its Item ID, and single-item edits to content and offer.
• Add items — single setup, setup by match for products already in the catalog, and bulk spreadsheet uploads. Item setup covers all three.
• Activity Feed — the status of every file you submit (setup, price, inventory, content), with per-item errors.
• Unpublished Items — every SKU that is not live, grouped by reason. Open it first for visibility problems.
• Listing Quality (under Growth Opportunities, sometimes reached via Analytics) — a per-item score (content, price competitiveness, shipping, published-and-in-stock, ratings and reviews — the split changes) plus the attributes Walmart wants improved. Content maintenance works it as a list.
• Help / Partner Support — the case queue and the knowledge base. Partner support cases covers when to open one.

Walmart rejects only what fails validation; everything else it accepts and then withholds. A row that clears validation — GTIN parses, image URL fetches, required attributes filled — shows success in the Activity Feed yet can still sit in Unpublished Items: the image failed compliance review, the price broke a pricing rule, the category is restricted, or a required attribute held a wrong value, not a blank. It waits until someone looks: this track's thesis.

So classify first; every problem is one of three kinds:

1. Content — the page misdescribes the product (wrong capacity, bad image). Fix with a content update.
2. Offer — price, quantity, shipping template, or fulfillment is wrong. Fix on the offer: a price or inventory update or the offer edit; fulfillment changes through its conversion flow.
3. Publishing — the item is not visible. Open Unpublished Items; the reason points to content, offer, or compliance (Catalog troubleshooting).

Misclassifying costs days: a price update does not fix a capacity error, and correct content does not publish an item.