Kit parent lines are excluded by design

This is expected behavior. When a kit order ships, Luminous explodes the kit into its component product lines — the individual SKUs that make up the bundle. Those component lines each receive a cost stamped at the time of shipment. The kit parent line itself carries no cost of goods, because no physical inventory is drawn from a kit SKU; the inventory (and therefore the COGS) belongs entirely to the components.

Writing a cost onto the kit parent line would double-count COGS: you would pay for the same goods once on the parent and again on the components.

Because a kit parent at $0 cost is correct by design, the Close the Books checklist excludes kit SKUs from the "No zero-cost sale items" check. The check's tooltip confirms this:

"All inventory sales items have a cost assigned (kits, non-inventory, and fee SKUs are excluded — kit COGS lives on the exploded component lines)"

What to check instead

If you are concerned about COGS coverage on kit orders, verify the component lines, not the kit parent:

  1. Go to Insights → Accounting → Close the Books and select the period.
  2. Under Order Integrity, find the zero-cost sale items check and click its expand arrow to see the list of affected SKUs and orders.
  3. If any of your kit's component SKUs appear there, those are real gaps. Follow the fix steps in "What are 'zero cost sale items' in the Close the Books report, and how do I resolve them?"
  4. The kit parent SKU will not appear here, whatever its cost. This is expected.

The same "virtual product" logic applies to inventory valuation reports — see Why Don't My Kits (Bundles) Appear in the Inventory Valuation Report? for more detail on how kit value is tracked through components.