Overview
If you sell a product in packs, cases or cartons on a marketplace (Amazon, Walmart, Shopify, etc.), Luminous needs two separate pieces of setup before a channel order deducts the right number of eaches:
- Packaging details on the SKU. These tell Luminous how many eaches are in a carton or pallet.
- The Selling Unit on the channel listing. This tells Luminous what unit the quantity on an incoming order from that channel is in.
Setting up only the first one is the most common cause of this symptom: "I set units per carton to 4, but when an Amazon order comes in for 1, Luminous only deducts 1 each instead of 4."
The conversion is in place, but the channel is still telling Luminous to read incoming orders as eaches, so it never gets applied.
Part 1: Packaging details on the SKU (the conversion)
Where: Inventory → SKUs → open the SKU → packaging fields (# of units per carton, # of cartons per pallet, Palletized)
What it does: When you enter these values, Luminous automatically creates the carton and pallet units of measure and the conversion rules for that SKU. For example:
| Field | Value | Conversion Luminous creates |
|---|---|---|
| # of units per carton | 4 | 1 carton = 4 eaches |
| # of cartons per pallet | 63 | 1 pallet = 63 cartons = 252 eaches |
What it does NOT do: It does not change how orders from your sales channels are interpreted. It only defines how to convert. It does not tell Luminous when to convert.
See also: How "Units Per Carton" and "Units Per Pallet" Work
Part 2: The Selling Unit on the channel listing (how orders are read)
Where: Settings → Integrations → select the channel (e.g. Amazon) → Manage Products → find the listing → Selling Unit column
What it does: When an order line comes in from that channel without a unit of its own, Luminous uses this value to decide what the order quantity means:
- Selling Unit = Each → an order for 1 deducts 1 each.
- Selling Unit = Carton → an order for 1 is converted with the SKU's carton conversion and deducts 4 eaches (using the example above).
Because this is set per channel listing, the same SKU can be sold as eaches on one channel and as cartons on another. You might sell singles on Shopify and a 4-pack on Amazon, both decrementing the same inventory.
You'll also see a Default Stock Unit column on this grid. That controls the unit used when stock levels are pulled in from an external warehouse connection. It does not affect how sales orders are read. For the "orders only decrement 1" issue, the Selling Unit column is the one to check.
Which setting wins?
When a channel order line doesn't specify its own unit, Luminous checks in this order and uses the first one that's set:
- The Selling Unit on the channel listing (Manage Products)
- The Selling Unit on the SKU (Inventory → SKUs → Units of Measure section)
So if the SKU's Selling Unit is Carton but the channel listing's Selling Unit is Each, orders from that channel are read as eaches. The listing setting takes priority.
Step-by-step: fixing a listing that should sell as cartons
- Confirm the conversion exists. Open the SKU and check that # of units per carton is filled in with the correct number.
- Open the channel's product list. Go to Settings → Integrations → [channel] → Manage Products and search for the SKU. More than one listing can map to the same SKU (e.g. a single, a 20-count and a 4-pack). Make sure you pick the right one.
- Set the Selling Unit. Change the Selling Unit on that listing from Each to Carton (or the matching unit).
- Test with a new order. The change applies to orders imported after you save it. Orders that already came in are not re-converted, so check and correct those separately if needed.
Things to watch for
- The unit must have a conversion for that SKU. If the listing's Selling Unit is Carton but the SKU has no carton conversion (units per carton is blank), Luminous can't convert the quantity. It is recorded 1-for-1, so 1 carton = 1 each.
- Kits are handled differently. Unit of measure conversion is not applied to kit SKUs. If the marketplace item is set up as a kit in Luminous, the number of each component deducted comes from the kit's component quantities, not from a carton conversion. Don't set up both for the same listing. Pick one model:
- Carton/UOM: the marketplace item is the same product, just sold in a bigger unit.
- Kit: the marketplace item is a bundle of other SKUs.
- One listing, one unit. If a channel sells the same SKU as both singles and packs, these are usually separate listings in Manage Products. Each one gets its own Selling Unit.
Quick checklist
- [ ] SKU has # of units per carton (and pallet, if used) filled in
- [ ] The correct channel listing in Manage Products has Selling Unit = Carton
- [ ] The listing isn't also set up as a kit for the same pack size
- [ ] A new test order deducts the expected number of eaches