Amazon Inventory Management in 2026: IPI, FBA Fees and Software

Good FBA stock control keeps each SKU in a safe band. Stay above 28 days of supply, below about 22 weeks of supply, and under 181 days of age. That keeps you clear of the low-inventory fee, the storage surcharge and aged inventory fees. Most FBA-only sellers with under 50 SKUs can do this with Amazon’s free tools. Buy amazon inventory management software when you sell on a second channel, run many open purchase orders, or need seasonal forecasts.

Key facts

• The low-inventory-level fee hits when both your 30-day and 90-day supply fall under 28 days. Third-party trackers report it now works per FNSKU (the FBA barcode) in 2026.
• Standard-size storage costs $0.78 per cubic foot from January to September. It jumps about 3x to $2.40 from October to December, per amzprep’s fee tracker (updated 18 August 2026).
• The 2026 holiday peak fulfillment fee averages $0.32 per unit. It runs from 15 October 2026 to 14 January 2027, Supply Chain Dive reported on 13 July 2026.
• Amazon calls Veeqo its free inventory software. Veeqo’s own pricing page puts automated channel sync in a plan from $19 a month.
• Paid tools run from $49 a month (RestockPro) to $1,199 a month (Cin7 Core Advanced), per each vendor’s pricing page on 22 September 2026.

What Amazon inventory management means in 2026

It means four jobs: send stock in, hold it, sell it, and recover what Amazon loses. Each job has its own fee. Send in too little and you pay the low-inventory fee. Send in too much and you pay storage, surcharges and aged fees.

Each job feeds the next. Ship 12 weeks of cover to one warehouse and you cut inbound cost but raise storage age. Ship 4 weeks and you walk into the low-inventory fee. Good stock control means picking the trade you can afford, one SKU at a time.

In the accounts we manage, we read three Amazon screens each week before we touch any tool. They are the Restock Inventory page, the Inventory Age report and FBA Capacity Manager. The next two sections show what those screens track.

IPI and FBA capacity limits in 2026

The Inventory Performance Index (IPI) is Amazon’s score for how well you run FBA stock. Amazon calls it “a credit score for inventory efficiency” on its inventory management page. The score rewards three habits: restock what sells, keep sane stock levels, and fix listing problems.

Third-party trackers report the minimum threshold is still 400. Amazon does not publish that number on any public page, so check your own score in Seller Central.

Capacity is the space Amazon lets you use, set each month in cubic feet. You see it in FBA Capacity Manager. Amazon bases it on your IPI, your sales speed and how fast stock turns. Industry reports say the formula tightened in May 2025, from about six months of projected sales to about five. Some sellers well above 400 reported large cuts. Treat 400 as a floor, not a goal.

Our rule: never sign a PO bigger than next month’s space plus what you will sell before the goods land. Space limits, not cash, stop most Q4 plans.

The 2026 FBA stock fees, with the math

Three fees punish bad stock levels, and a fourth rises every fall. Amazon’s 2026 fee update added no new fee types and raised FBA fees by an average of $0.08 per unit from 15 January 2026. The stock fees below hit your margin much harder.

Low-inventory-level fee

Amazon charges it when both your 30-day and 90-day historical days of supply fall under 28 days. Days of supply is the units you hold each day on average, divided by the units you ship each day. Third-party trackers report a fee of about $0.32 to $1.11 per unit for standard size.

Here is the math on an example SKU. You hold 900 units on average and ship 40 a day. That is 900 divided by 40, or 22.5 days. You sit below 28, so you are exposed.

Now solve it backwards. At 40 a day, 28 days of cover means 1,120 units held on average. You are 220 units short. Clear either window and the fee stops, because it needs both under 28.

New sellers get a one-year exemption from this fee and the storage surcharge, per Amazon. Slow sellers stay exempt too, Amazon said in its 2026 update.

Storage, the utilization surcharge and aged stock

Monthly storage bills your average daily cubic feet. The storage utilization surcharge adds to that when you hold about 22 weeks of supply or more, per novadata. Third-party trackers say the surcharge can lift standard-size storage to $2.66 per cubic foot off-peak and $4.28 in Q4.

Aged inventory fees start at 181 days in storage, per Amazon’s FBA page. For 2026, trackers report 12 to 15 months costs the greater of $0.30 per unit or $6.90 per cubic foot. They also report a new 15-month-plus band at $0.35 per unit or $7.90 per cubic foot. Amazon’s own help pages sit behind a login, so confirm both bands in Seller Central.

Amazon also flags too much stock sooner than the fees do. Its inventory page counts a SKU as excess at over 90 days of supply, or with any unit aged over 90 days. That 90-day flag is your early warning.

A worked Q4 replenishment example

It is 22 September. The low-inventory fee and Q4 storage pull against each other. Here is how we size a holiday order for one SKU. The numbers are an example, so swap in your own.

The SKU sells 40 units a day now. Last year, November and December ran at 1.75x, so we plan 70 a day from 1 November to 31 December. FBA holds 3,000 units today. Nothing is on the water.

Step	Math	Result
Sales from 22 Sep to 31 Oct	39 days x 40	1,560 units
Stock left on 1 Nov	3,000 minus 1,560	1,440 units
How long that lasts at peak	1,440 divided by 70	20.6 days, out by about 21 Nov
Ocean lead time	30 days make + 30 days sea + 14 days receiving	74 days, lands 5 Dec
Air lead time	30 days make + 7 days air + 14 days receiving	51 days, lands 12 Nov
Air order: gap to 5 Dec	34 days x 70, minus 1,440, plus 7 days safety (490)	1,430 units
Ocean order: 5 Dec to 31 Jan	(27 x 70) + (31 x 40) + 560 safety, minus 490 left from air	3,200 units

Sea freight alone lands on 5 December, two weeks after the stockout. That gap costs about 980 lost sales (14 days x 70) plus lost rank. So the plan splits the order. Air covers the gap and ocean covers the rest.

Now check the fees. On 1 November the SKU holds 20.6 days of peak supply, under 28. The 90-day window still carries September’s higher cover, so the fee should not trigger. Watch it in your fee preview anyway.

Next, storage. Say each unit is 0.1 cubic feet. The 3,200 ocean units fill 320 cubic feet. At the $2.40 peak rate, that is up to $768 for December if nothing sold. The same space costs about $250 a month from January at $0.78. Stock sells down fast in December, so the real bill runs lower.

Finally, age and surcharge. By 1 January you hold about 45 days of supply at 40 a day. That sits far under 22 weeks and 181 days.

The lesson for next year: to land by 15 October, before the peak fee starts, place the ocean PO by 2 August. We add a two-week buffer and aim for mid-July.

Do you need paid software? The native-first test

Most FBA-only sellers with under about 50 SKUs do not need paid Amazon inventory management software yet. Amazon’s free tools cover the math above if you read them every week. Run this test before you buy anything.

Answer yes or no to each line:

• You sell on one channel, and FBA fills most orders.
• You have fewer than about 50 active SKUs.
• You have five or fewer open purchase orders at once.
• Your sales do not swing hard by season.
• Someone checks Restock Inventory and the Inventory Age report each week.

All yes? Stay native. Restock Inventory gives reorder advice by SKU. The Inventory Performance dashboard shows sell-through, IPI and aging alerts. The Inventory Age report shows what nears 181 days. Veeqo’s free plan adds shipping labels if you also ship orders yourself.

One or more no? You have a job Amazon’s tools do badly. A second channel drawing on the same stock causes oversells. Many open POs get lost in a spreadsheet. Seasonal SKUs need forecasts that look back a full year.

Amazon inventory management software compared (2026)

If the test says buy, the table below compares seven tools on owner, price and fit. We took every price from the vendor’s own page on 22 September 2026. Owners matter, because a buyout can change a tool’s plans and support.

Tool	Owner	Price (22 Sep 2026)	Best for
Veeqo	Amazon	Shipping free; Inventory plan from $19/mo; High Volume from $350/mo	Multichannel sellers who want Amazon’s own tool
RestockPro	eComEngine	From $49/mo, by volume; 30-day trial	FBA private label reorder planning
InventoryLab (Threecolts Seller 365)	Threecolts	$69/mo; Teams $129; Pro $199	Arbitrage and wholesale sourcing and listing
SoStocked	SPS Commerce	ProfitFlow $97/mo; with inventory from $250/mo	Private label forecasting with AWD and 3PL stock
Sellbrite	GoDaddy	Free (30 orders); $29, $79, $179/mo; FBA orders not counted	Listing and stock sync across Walmart, eBay, Etsy, Shopify
Cin7 Core	Cin7	$349, $599, $1,199/mo (monthly billing)	Brands with warehouses, B2B and many channels
Linnworks	Linnworks	Quote only, priced by order volume	High-order multichannel sellers

Two details the “Top 15” lists miss. First, Sellbrite does not count FBA orders toward its plan limits, but its FBA add-on costs $19 a month more, per its pricing page. Second, Amazon describes Veeqo as free inventory software. Veeqo’s own pricing page lists “automated inventory sync across channels” and “demand forecasting” in the paid Inventory plan. Budget $19 a month if you need sync.

Forecastly used to sit on these lists. We could not confirm its current owner or price, so we left it out.

Which software feature prevents which fee

Each stock fee has a trigger, and each trigger maps to one feature. Buy the feature that stops your biggest fee, not the longest list. This matrix is what we use when a client asks which tool to pick.

Fee	Trigger (2026)	Feature that prevents it	Free Amazon view
Low-inventory-level fee	30-day and 90-day supply both under 28 days, per FNSKU [3P]	Days-of-cover alerts per FNSKU, reorder points that include lead time	Restock Inventory, fee preview
Storage utilization surcharge	About 22+ weeks of supply [3P]	Weeks-of-cover caps on POs, overstock alerts	Inventory Performance dashboard
Aged inventory surcharge	From 181 days; 12 to 15 month and 15+ month bands [3P]	Age buckets, markdown and removal alerts	Inventory Age report
Q4 peak storage	$2.40 vs $0.78 per cu ft, Oct to Dec [3P]	Landing-date planning, AWD staging with auto replenishment	Capacity Manager, Restock
Holiday peak fulfillment fee	15 Oct 2026 to 14 Jan 2027, avg $0.32/unit	None; price it in	Revenue Calculator
Stockouts on other channels	Stock sold twice	Real-time multichannel sync	None (Veeqo paid plan)

The last two rows matter. No tool removes the peak fulfillment fee, so it belongs in your Q4 price, not your software budget. Oversells are the one risk Amazon’s free screens miss.

Pick by business model

The right tool depends on how you buy and where you sell. Here are our picks by model.

Private label, FBA only. Your risk is ordering too little or too much from one factory. Start native. Move to RestockPro when forecasts get hard. Pick SoStocked when you hold stock in AWD or a 3PL and need one plan across all of it.

Online and retail arbitrage. Your risk sits at buying and listing, not forecasts. InventoryLab fits, because it tracks buy cost and lists many small lots fast. Keep your supplier invoices, because Amazon rejects many retail receipts.

Wholesale. You reorder known brands on steady cycles. Restock Inventory plus a PO sheet covers small catalogs. RestockPro handles larger ones.

Multichannel. Your risk is selling one unit twice. Sellbrite suits small sellers adding Walmart, eBay or Etsy. Linnworks fits high order volume. Cin7 Core fits brands with their own warehouse or wholesale buyers. Veeqo’s paid plan is the cheapest sync if Amazon stays your main channel.

If you also run a Walmart store, our Walmart account management team works from the same stock plan.

Where this advice could be wrong

Several thresholds here come from third-party trackers, not Amazon. The IPI floor of 400, the per-FNSKU fee rule, the 22-week surcharge line and the 2026 aged bands all sit behind the Seller Central login. Check your own fee preview before you act on any of them.

The 50-SKU line is our rule of thumb, not a law. A 20-SKU seller with wild seasons may need forecasting sooner. A 100-SKU wholesale seller with flat demand may never need it.

The Q4 example uses made-up sales and lead times. Your supplier, freight lane and receiving delays will change every date in it. If your receiving ran late last Q4, add more buffer.

Stock that Amazon loses is a separate job. See our guide to FBA reimbursements for claim paths. For the full fee stack beyond stock, read Amazon seller fees in 2026. Want a second set of eyes on your restock plan? Our Amazon account management team starts with a free audit, and you keep every file and login.

Frequently asked questions

What is the best inventory management software for Amazon sellers?

The best Amazon inventory management software depends on your model. For FBA private label, RestockPro (from $49 a month) or SoStocked fit. For arbitrage, InventoryLab ($69 a month) fits. For multichannel sellers, Sellbrite, Linnworks or Cin7 Core fit. Sellers with under 50 FBA SKUs often need none.

Does Amazon have its own inventory management system?

Yes. Amazon gives every Professional seller free tools: the Inventory Performance dashboard, Restock Inventory, the Inventory Age report and the IPI score. Amazon also owns Veeqo, which adds shipping for free and multichannel sync on a paid plan. These tools cover most single-channel FBA sellers.

Is Veeqo free?

Partly. Veeqo’s shipping plan is free because carriers pay it a commission on labels. Its Inventory plan, which adds automated sync across channels and demand forecasting, starts at $19 a month. The High Volume plan starts at $350 a month. Amazon owns Veeqo and bought it in 2021.

How much does inventory software cost?

Prices run from free to over $1,000 a month. As of September 2026, RestockPro starts at $49 a month and InventoryLab costs $69. SoStocked starts at $97, or $250 with inventory tools. Cin7 Core runs $349 to $1,199, and Linnworks quotes by order volume.

Can one tool sync Amazon, Shopify and Walmart stock?

Yes. Sellbrite, Linnworks, Cin7 Core and Veeqo’s paid Inventory plan all sync stock across Amazon, Shopify and Walmart. Each sale on one channel lowers the count on the others, which stops oversells. Check that your plan includes FBA stock, since Sellbrite charges $19 a month extra for its FBA add-on.

What is a good IPI score in 2026?

Third-party trackers report the minimum threshold is 400, though Amazon does not publish it openly. Treat 400 as a floor. Sellers above it still saw capacity cuts after the May 2025 change. Aim higher by restocking top sellers, clearing aged stock and fixing stranded listings each week.

How are FBA capacity limits calculated?

Amazon sets capacity monthly in cubic feet, shown in FBA Capacity Manager. It weighs your IPI, your sales speed and how fast stock turns over. Industry reports say the projection window shrank from about six months of sales to five in May 2025. Your limit can change every month.

How do I avoid the low-inventory-level fee?

Keep at least 28 days of supply in your 30-day or 90-day window. Multiply daily units shipped by 28 to find the floor. At 40 units a day, hold 1,120 on average. Auto replenishment from AWD also avoids it, and new sellers get a one-year exemption.

SoStocked or RestockPro: which should I choose?

Choose RestockPro for simple FBA reorder planning at a lower price, from $49 a month. Choose SoStocked when you forecast across FBA, AWD and a 3PL, or want profit tracking too. Its ProfitFlow plan costs $97 a month, and inventory planning starts at $250.

What is AWD and is it worth it?

AWD is Amazon Warehousing and Distribution, Amazon’s bulk storage that refills FBA for you. It suits sellers who ship large ocean orders and cannot fit them inside FBA capacity. Auto replenishment from AWD also avoids the low-inventory fee. Price it against your own 3PL before you switch.

How much does FBA storage cost in 2026?

Standard-size storage costs $0.78 per cubic foot a month from January to September and $2.40 from October to December, per third-party trackers. Oversize runs $0.56 and $1.40. Utilization surcharges can raise standard size to $2.66 off-peak and $4.28 in Q4. Confirm current rates in Seller Central.

When does the aged inventory surcharge start?

Aged inventory fees start at 181 days in storage. Trackers report a 12 to 15 month band at $0.30 per unit or $6.90 per cubic foot, whichever is greater. A new 15-month-plus band costs more. Cut the price, remove or liquidate slow units before day 181.