Inventory allocation: split one warehouse’s stock across channels without overselling
Sell the same SKU on Amazon, Shopify, and eBay at once: decide how much each channel may sell, keep a safety buffer, and let the system push the right number to each channel.
You keep one pile of stock in the warehouse, but the same SKU is listed on Amazon, Shopify, and eBay at the same time. If every channel shows the full quantity, the three of them can sell the same unit twice — that is overselling. Inventory allocation splits the pile before anything is pushed out: you decide how much each channel is allowed to sell, and the system sends each channel only its share.
Three ways to split the stock#
Proportional — split by percentage
Each channel gets a fixed share of the pool — when the total goes up or down, every channel’s number moves with it.
Example — 200 units in the pool: Amazon 30% → 60 units, Shopify 50% → 100 units, eBay 20% → 40 units.
Fixed quantity — a hard cap
No matter how much stock there is, this channel only ever sees N units — it can never sell more than that, which makes it the safest option for strict channels.
Example — Amazon fixed at 100: a pool of 200 sends Amazon 100; the other channels split the remaining 100.
Catch-all — take whatever is left
After the fixed and proportional channels take their share, this channel gets everything left over. Only one channel per SKU can be the catch-all.
Example — pool of 200: Amazon fixed 100, Shopify 50% of the remaining 100 → 50, eBay catch-all → the last 50.
The split always runs in this order: safety stock comes off first, then fixed-quantity channels, then proportional channels (their base is whatever is left after the fixed ones), and the catch-all takes the rest.
Safety stock: stock nobody gets to sell#
Safety stock is a slice of inventory the system never allocates to any channel, no matter what. It comes off the top: allocatable pool = available stock − safety stock.
Why keep it? Counts are never perfect — a miscount, goods still in transit, or a sudden return can leave the shelf emptier than the numbers say. Without a buffer, that gap becomes an oversell; with one, the surprise is absorbed before any channel feels it.
- Percentage (e.g. 10%): scales up and down with your stock — good for steady sellers. 200 units available → 20 kept back, 180 to split.
- Fixed units (e.g. 15): simple and predictable — good for hot sellers (a percentage would lock away too much) or slow movers. 200 units available → 15 kept back, 185 to split.
If you set both, the fixed number wins. You can also set a stricter safety stock for one channel (e.g. Amazon), which overrides the global default for that channel.
Set it up in four steps#
- Open Integration → Inventory Allocation in the left menu.
- Set the global default: which strategy unconfigured channels follow, and the global safety stock. Anything you don’t configure below follows this.
- Configure each channel: click its card, pick one of the three strategies, enter the number. Optionally set a channel-level safety stock and a priority — when stock runs short, lower-priority channels get squeezed first.
- (Optional) Give hot SKUs their own rules: add SKU × channel overrides — e.g. SKU-A on Amazon fixed at 100 units. Layers apply as a whole: once a SKU has any override, the entire SKU layer is used for it — the channel-default and global-default layers are skipped for that SKU (fields are never inherited from lower layers). A channel with no override at that layer is pushed its original number, never blocked.
FAQ#
- What if my percentages add up to more than 100%? — The page will not save it: “percentage channels can’t total more than 100%, currently {n}%”. Lower the numbers until the total is 100% or less, then save.
- What if I don’t configure any rules? — Nothing changes: the full available quantity is pushed to the channel, exactly like before. Allocation only kicks in where you set rules; unconfigured SKUs and channels behave the old way.
- A channel got fewer units than I configured — why? — Two usual suspects: a more specific layer won (layers apply as a whole — the first layer with any rules is used in full: SKU × channel overrides beat channel defaults beat the global default, and lower layers never fill in the gaps), or stock ran low and the system squeezed lower-priority channels to avoid overselling (squeeze order: catch-all first, then lower-priority percentage channels; fixed-quantity channels are squeezed last). The allocation log shows the exact split each time.