Low-inventory fees are per FNSKU (January 2026) — parents no longer hide a starved child

PPC implication

You cannot rank a child into a surcharge and call it growth. Exact campaigns must be child-specific enough to pause the starved size without killing the in-stock siblings. Parent-level auto is how you donate the fee on every click.

1. Export days of supply by FNSKU.
2. Any advertised child under the live threshold: pause ranking, keep a trickle of defense if it is a brand term.
3. Restock or inbound. Only then restore bids against the new break-even (fee included).

What January 2026 sharpened

Low-inventory level fee is a 2024-era charge, not a brand-new 2026 fee type. In the January 2026 US window Amazon evaluated it at FNSKU / child and expanded toward bulky. A healthy parent with one starved size still pays on units sold of that size until days of supply recover. The common lookback operators use is about 28 days — confirm the live help page. IPI can look fine while a child burns a surcharge on every sale you also advertised.

How to confirm

Inventory Planning by FNSKU, not by parent. Fee Preview on advertised children. Restock report. If a child is under the live threshold and has a ranking campaign, pause ranking. Keep a trickle of brand defense only if it is a brand term and the offer is in stock. Restock or inbound. Restore bids against break-even that includes the fee until days of supply recover.

Why parent-level auto is the leak

Parent auto cannot pause the starved size without starving the in-stock siblings — or it keeps buying clicks on the empty size. Child-level exact (or at least ad groups that match FNSKUs) is how you turn the fee off without killing the rest of the variation. Harvest still runs at search-term level. Inventory is a bid input, not a warehouse sidebar.

Related: January fee window, inbound placement, Inventory & IPI.

PPC implication

A starved child with a ranking campaign is a donation. Pause ranking on that FNSKU. Do not raise bids to “sell through faster” if the fee makes contribution negative. Restock, or stop buying Page 1. Brand defense can stay on a brand term if the offer is in stock. Restore exact only after days of supply recover and break-even includes the fee until then. Confirm the live help page for the lookback and bulky rules — they have moved before.

How to read the surcharge without a blog table

Low-inventory is a 2024-era fee that January 2026 sharpened at the child FNSKU and toward bulky. IPI can be green while one starved size pays on every sale you advertised. The common lookback operators use is about 28 days — confirm the live help page. Inventory Planning by FNSKU, Fee Preview on advertised children, restock report. If the child is under the live threshold, pause ranking; keep a trickle of brand defense only if the offer is in stock. Restock. Restore bids against break-even that includes the fee until days of supply recover. Parent-level auto cannot pause the empty size without starving siblings — or it keeps buying clicks on the empty size. Child-level exact is the fix.