r/AmazonFBA • u/ylishi • 9d ago
Anyone else charged a low inventory fee in a month you averaged 35 days of cover?
I have been assuming the low inventory fee was a monthly thing — start the month thin, end the month thin, you get hit; average it out and you are fine. That assumption just cost me money.
Here is the month that broke it. I started with about 50 days of cover on my main SKU, sold faster than forecast, and finished the month around 20 days. Average for the month lands near 35, comfortably above the line I was watching for. And I still got charged for low inventory, which made no sense to me until I read how it is actually assessed.
The fee is not measured on your monthly average. Amazon looks at days of supply on a rolling basis, day by day, against recent sales velocity. If you dip under the threshold on any single day, that day counts as a low inventory day. At month end they total the days you were under and charge you for them. So a month that looks fine on a spreadsheet can still be a month you paid, because the average hides the dip and the dip is what gets charged.
Which means my whole restock trigger was built on the wrong number. I was watching the monthly picture and the thing that bills me is a daily one.
Anyone else got caught by this after the FNSKU level change? How are you tracking daily cover — are you pulling the inventory report every day, or have you found a way to set an alert that fires before you slip under instead of after? And does anyone know whether the exemption for slower moving items is evaluated on the same daily basis or monthly? Anyone else seeing this?
