Inventory management for Amazon sellers, set against every FBA fee.
Shelfcrest runs inventory management for Amazon sellers whose FBA stock costs too much or runs out at the wrong time: demand forecasting, inventory planning and restocks set against FBA capacity limits, the Inventory Performance Index and Amazon's fees.
What inventory management for Amazon sellers covers
Inventory management for Amazon sellers on FBA works out how much stock to send, when, and how, so a product neither runs out nor sits as slow moving inventory in a fulfillment center. That sounds simple until the fees and the limits are added: monthly FBA capacity limits, the Inventory Performance Index, inbound placement fees, storage fees and a fee for running too low.
Every one of those is set by Amazon and changes during the year. Too little stock, and a product can pay the low-inventory-level fee and lose sales while it is out. Too much, and it counts as excess inventory, weighs on the IPI score and builds up storage costs. The right level sits between them.
As an Amazon FBA consultant, Shelfcrest sets inventory levels for each SKU from your own sales velocity and demand forecasting, then plans replenishment, shipment splits and timing against Amazon's current rules, with cash flow in mind. Inventory management is also part of full account management.
Six signs your Amazon inventory management needs help
Low-inventory-level fees on your statement
Amazon charges it when both the 90 day and 30 day days of supply fall below 28 days.
A best seller keeps running out
Stockouts cost sales and the organic rank the ads were building, and they are the most expensive inventory decisions to get wrong.
Excess inventory warnings
Amazon counts an item as excess once it holds more than 90 days of supply against forecast demand.
Stranded units in the fulfillment center
Units without an active listing cannot be bought, and they still cost storage.
Placement fees you did not plan for
Sending to a single location costs a fee per unit; splitting across five or more locations can cost none.
A restock that will not fit this month
Capacity limits are set monthly, so a late plan can leave stock with nowhere to go.
The FBA fees and limits an inventory plan has to fit
| Rule | What Amazon says | Direction | What is done |
|---|---|---|---|
| Low-inventory-level fee | Charged when both the 90 day and 30 day historical days of supply are below 28 days | Keep more stock | Restocks timed so days of supply stay above 28 |
| Excess inventory | An item is excess with more than 90 days of supply on forecast demand | Keep less stock | Orders sized to sell through inside the window |
| Storage fees | Monthly inventory storage fees, and long-term storage fees | Keep less stock | Slow movers reduced before they age |
| FBA capacity limit | One limit per storage type each month, usually announced in the fourth week | A ceiling | Restocks planned against next month's limit |
| Inbound placement fee | A fee for sending to one location; no fee with Amazon-optimized splits of five or more identical cartons per item | How to ship | Cartons packed to qualify for the no fee option where it pays |
Amazon's own guideline in the Inventory Performance help is to hold enough stock to cover 30 to 60 days of expected sales. That band is where the low stock fee and the excess inventory line both stay out of reach.
Eight areas of FBA inventory consulting, and the question behind each
- Demand forecasting
- How many units does each SKU sell per week, what do the sales trends look like across the year, and how much safety stock does that call for?
- Days of supply
- Is every product between the low stock fee line of 28 days and the 90 day excess line?
- Capacity limits
- Will next month's restocks fit inside the FBA capacity limit Amazon has set?
- Shipment splits
- Does it pay to pack for Amazon-optimized splits, or to pay the placement fee and ship to one location?
- Stranded inventory
- Which units are sitting in fulfillment centers without an active listing, and what are they costing in storage and lost sales?
- Slow moving products
- Which slow moving products will reach long-term storage fees, and what is the plan to reduce them first?
- Ads and stock together
- Are PPC budgets cut before a product runs low, and raised when a restock lands?
- Supplier lead time
- Does the reorder point allow for production, freight and receiving time?
Days of supply, the number every FBA restock and inventory level is built on
Days of supply is how long your stock levels will last at the current sales velocity. Amazon uses it for the low-inventory-level fee and for excess inventory, so it is the number an FBA consultant manages first. Keep it above 28 days and under 90, ideally inside Amazon's own 30 to 60 day guideline.
Days of supply = units available / average units sold per day
Reorder point = daily sales × (lead time in days + safety days)
Sell-through = units shipped over 90 days / average units held
Worked example, illustrative
A product sells 20 units a day. Production, freight and receiving take 45 days, and the brand holds 10 days of safety stock.
- The reorder point is 20 × (45 + 10) = 1,100 units: when stock drops to 1,100, the next order must go.
- At 1,100 units, days of supply is 1,100 / 20 = 55 days, inside Amazon's 30 to 60 day guideline.
- When the order lands 45 days later, 200 units of safety stock remain. An order of 1,400 lifts stock to 1,600 units, or 80 days, still under the 90 day excess line.
- Packed as five identical cartons per shipment, the order can go in with no placement fee under Amazon-optimized splits.
| Size tier | Weight | Minimal splits fee per unit | Amazon-optimized splits |
|---|---|---|---|
| Small standard | 8 oz or less | $0.14 to $0.32 | No fee |
| Small standard | 8+ oz to 16 oz | $0.16 to $0.32 | No fee |
| Large standard | 12 oz or less | $0.20 to $0.40 | No fee |
| Large standard | 1.5+ lb to 3 lb | $0.34 to $0.60 | No fee |
| Large standard | 15+ lb to 20 lb | $0.55 to $1.90 | No fee |
What an FBA inventory audit finds
Illustrative examples on an unnamed account. Not client results.
A best seller paying the low-inventory-level fee every month
Restocks arrive after days of supply falls below 28
Move the reorder point up by the lead time the supplier actually delivers
Four slow products holding 150 days of supply
Excess inventory and storage fees grow while the units age
Stop reordering, lower the price or run ads to sell through, then decide what to remove
Every shipment sent to a single location
A placement fee on every unit, paid out of habit
Pack for Amazon-optimized splits where the product and the carton count allow it
Ads at full budget on a product about to stock out
Clicks bought for a product that will not be there
Tie ad budgets to days of supply, and cut them before the product runs low
The first 30 days, then every week
Week 1: access and the picture
You authorize Shelfcrest as a service provider in Seller Central for inventory and reports. Every SKU is read: days of supply, excess, stranded units, fees paid in the last months. Output: a ranked list of what stock is costing you.
Week 2: costly problems first
Stranded units get their listings fixed, excess stock gets a plan, and products paying the low-inventory-level fee get their next restock moved forward.
Week 3: forecast and reorder points
A forecast for each product from your own sales history, and a reorder point that allows for your supplier's real lead time.
Week 4: restock calendar and report
A restock calendar set against next month's FBA capacity limit, with the shipment split for each shipment and its fee. The first report records where inventory started.
Every week after
Days of supply, open shipments, stranded units and ad budgets against stock, in that order.
Every month
When Amazon announces the next capacity limit, usually in the fourth week, the calendar is checked against it before anything is ordered.
Included in FBA inventory consulting
- Days of supply for every product, against the 28 and 90 day lines
- A demand forecast and reorder point for each product
- A restock calendar set against FBA capacity limits
- Shipment split choices with the placement fee for each
- Stranded inventory found and its listings fixed
- A plan for excess and aging stock before long-term storage fees
- Ad budgets tied to stock, so no clicks are bought for empty shelves
- A weekly check and a written monthly report
- Your data, forecasts and reports stay yours
Supplier negotiation, freight booking and prep work are not included. For inventory planned together with listings, ads and account health, see full account management. For money Amazon owes on lost or damaged units, see the FBA reimbursement service.
A 10-step Amazon inventory management check you can run this week
- Monitor inventory on the Inventory Performance dashboard: note excess, stranded, sell-through and in-stock.
- Download your FBA inventory reports and list every SKU with less than 28 days of supply.
- List every product with more than 90 days of supply.
- Check your statement for low-inventory-level fees and placement fees last month.
- Fix the listings behind any stranded units.
- Check the Capacity Monitor for next month's limit.
- For your top product, work out the reorder point: daily sales × (lead time + safety days).
- Check whether your cartons could qualify for Amazon-optimized splits.
- Compare each ad budget with the days of supply behind it.
- Write down your supplier's real lead time from the last three orders, not the quoted one.
If that check shows more fees than you expected, that is where inventory management, or an Amazon FBA consultant, pays for itself. The ACoS calculator helps with step nine.
Doing it yourself, inventory software, a 3PL, or an Amazon FBA consultant
| Option | Works well when | Where it breaks |
|---|---|---|
| Doing it yourself | A few products with steady sales | Fee rules change during the year, and restocks slip when sales spike |
| Inventory software | Many SKUs and a need for daily forecasts | Software forecasts; it does not decide which product deserves the cash or tie the ads to stock |
| Prep center or 3PL | Storing stock outside Amazon and sending it in waves | They move boxes; the plan of what to send and when still has to come from somewhere |
| Amazon FBA consultant | Fees and stockouts cost more than a plan would | Consultants who forecast without your own sales data |
Who this service is for
A good fit
- Private label brands on FBA paying low stock or placement fees
- Brands with best sellers that run out, or slow sellers that age
- Brands launching products that need a first restock plan
Not a fit
- Merchant fulfilled only accounts with no FBA stock
- Brands looking for freight booking or a warehouse
- Vendor Central only accounts
What FBA inventory management costs at Shelfcrest
FBA inventory consulting: quoted after the audit
FBA inventory consulting is quoted in writing after the free audit, as a flat fee set by the number of products and how often they restock. It is never a share of fees saved. The monthly plans are on the pricing page.
Inventory management for Amazon sellers FAQ
What does inventory management for Amazon sellers include?
Demand forecasting, inventory planning and replenishment for FBA stock: how much to send, when and how, with inventory tracking against sales trends. It is set against Amazon's capacity limits, the Inventory Performance Index, placement fees, storage fees and the low-inventory-level fee.
What does an Amazon FBA consultant do for inventory?
An Amazon FBA consultant plans the stock a brand keeps in Amazon's fulfillment network: how much to send, when and how, set against Amazon's capacity limits, the Inventory Performance Index, placement fees, storage fees and the low-inventory-level fee.
What is the low-inventory-level fee?
An FBA fee Amazon charges when a product's historical days of supply is below 28 days on both the 90 day and the 30 day measure. New Professional sellers are exempt for 365 days after their first inventory is received, and new-to-FBA products for 180 days.
What is a good number of days of supply?
Amazon's Inventory Performance help suggests enough stock to cover 30 to 60 days of expected sales. Under 28 days risks the low-inventory-level fee, and over 90 days counts as excess.
What is the Inventory Performance Index?
Amazon's measure of how well FBA inventory is managed, built from excess inventory, stranded inventory, sell-through and in-stock rate. It is shown on the Inventory Performance dashboard.
How do I avoid the inbound placement fee?
Amazon charges no placement fee for Amazon-optimized shipment splits, which need at least five identical cartons or pallets per item, each with the same quantity and mix. Sending to a single location costs a fee per unit.
What is stranded inventory?
Units in a fulfillment center without an active listing. They cannot be bought, and they still count against storage. Fixing the listing makes them available again.
What are FBA capacity limits?
A monthly limit on how much inventory you can send to and store at Amazon, one per storage type, usually announced in the fourth week of the month.
How often should I restock?
At the reorder point: daily sales times the supplier's real lead time plus safety days. The calendar follows from that, not from a fixed monthly habit.
Should ads change when stock runs low?
Yes. Buying clicks for a product about to stock out wastes money and can hurt the listing. Budgets are tied to days of supply.
Do you use inventory management software?
Software helps track inventory and forecast demand, and your own inventory reports in Seller Central are the starting data. Tools do not decide which SKU deserves the cash, or when to cut ad spend before stockouts, so the restocking decisions stay with a person who reads the numbers.
How does good inventory management help FBA sellers?
It helps reduce lost sales from stockouts, cuts fees from excess and low stock, and protects the customer experience, because a product that is always in stock keeps its reviews and its rank. It also frees cash that would otherwise sit in fulfillment centers.
Do you work with prep centers and 3PLs?
Yes, as part of the plan. The consultant decides what to send and when; the prep center or 3PL does the physical work.
Do you manage merchant fulfilled orders?
Inventory consulting is for FBA stock. Merchant fulfilled performance is covered in full account management.
What access do you need?
Service provider access in Seller Central for inventory and reports, and your supplier lead times and costs.
What happens if we stop?
The forecasts, the restock calendar and the reports stay yours.
Get a free FBA inventory audit.
Send your store link. You get a written audit: days of supply by product, fees paid, stranded and excess stock, and the first restock changes to make.