Inventory Forecasting for Amazon Brands: One Monthly S&OP Plan Across FBA Capacity, AWD, a 3PL and Suppliers

By Bernardo Campelo, Forbes Business Council E-Commerce Leader, Amazon SPN Certified provider, Amazon SP-API authorized partner, and Founder of PrepVia.

As of October 29, 2026, Amazon sets your FBA capacity one month at a time: one limit for each storage type, typically announced during the fourth week of the month, according to its FBA capacity limits page. Amazon says the limits exist partly so you can "plan how much inventory to procure and manufacture." That makes Amazon's calendar the starting point for any inventory forecast you build.

Supply chain teams call that planning rhythm sales and operations planning, or S&OP. For a brand that sells through Amazon, the monthly meeting has to reconcile four clocks that do not tick together: Amazon's demand forecast, the monthly FBA capacity limit, the automatic replenishment of Amazon Warehousing and Distribution (AWD), and the lead time from your supplier through your 3PL. The calendar below is built from the dates Amazon publishes.

Every date and name below was checked on October 29, 2026 against Amazon's Seller Central help pages and Seller Forums announcements, About Amazon, the Hong Kong government and China's State Council, linked where they first appear. Fee figures are Amazon's 2026 rates, and Amazon edits help pages without notice, so open the live page before you lock a number.

Four Clocks That Do Not Tick Together

A generic forecast answers one question: how many units will sell. On Amazon, demand is only one constraint. Amazon decides how much space you get, AWD decides how fast stock moves into FBA, and your supplier decides when the next production run ships.

"Today, I see more e-commerce businesses constrained not by demand but by systems that can’t keep up."

Bernardo Campelo, in a Forbes Business Council article, March 16, 2026

For an Amazon brand, those systems are partly Amazon's and partly your own. The monthly meeting puts all four clocks on one page, then makes the decisions Amazon will not make for you.

The Demand Clock: Start With the Forecast Amazon Already Runs

Amazon's demand forecast tool estimates demand for your products "for up to 40 weeks," with a mean line and an optimistic line that demand is expected to stay at or below 90% of the time. You can download 26 weeks of weekly forecasts for your FBA portfolio in one file, labeled PMean and P90, and Amazon says the forecast refreshes weekly.

Amazon is direct about the limits. It calls the forecast "a planning tool, not a guarantee of future orders," says it "may not have visibility into your upcoming advertising campaigns and external marketing efforts," and advises using it alongside your own insights. That is the demand review: start from Amazon's file, then add launches, promotions, ad budgets and sales outside Amazon.

The forecast also drives what Amazon recommends back to you. Amazon calls it "one of the key inputs" to its restock recommendations, and its Minimum Inventory Level per FNSKU is updated weekly from the forecast and your replenishment settings: lead time, from creating a shipment to its receipt at a fulfillment center, and replenishment frequency. On its Customize SKU settings page, Amazon warns that if the default frequency is four weeks but you replenish weekly, "the recommendations will be four times too high."

Two more guidelines belong in the review. Amazon's inventory performance guidance is to cover 30 to 60 days of expected sales, and it treats more than 90 days of supply against forecast as excess. For products without a minimum recommendation, Amazon says to plan at least 28 days of cover.

One gap is structural. On the FBA Inventory page, "Total inventory supply" adds the FBA units already inside Amazon's network to your AWD units, including units inbound to AWD. Open FBA shipments sit in a separate Inbound count, and stock at your 3PL, freight on its way there and units in production are not in Amazon's numbers at all, so the meeting has to add them.

The Capacity Clock: One Limit per Storage Type, per Month

Amazon sets one limit per storage type per month: standard-size, oversize, apparel, footwear and extra-large. Typically in the fourth week, Amazon confirms the limit for the coming month, reaffirms or adjusts the estimate for the month after, and estimates the third month. The Capacity Monitor on the FBA dashboard shows all three.

The inputs show which levers are yours. Amazon says the limit is influenced by your IPI score and by "historical sales volume, seasonal and peak selling periods for your products, forecasts for your ASINs, the new selection that you carry, deals that you’ve scheduled, fulfillment center capacity, and shipment lead time." Launches, deals and lead time are partly in your hands; fulfillment center capacity is not.

The hard rule is the block. If on-hand inventory plus shipments on the way would exceed the limit, Amazon blocks new shipments, and open shipments count toward usage until you cancel them. Removal orders free capacity within 24 hours, and capacity cannot be traded between storage types.

When the limit is too small, the tool is Capacity Manager. You request space for a future period, never the current one, at a maximum reservation fee per cubic foot; Amazon grants the highest fees first, may open the space up to one month early, and charges the fee after the period ends, so capacity granted for October is billed in early November. Sales made with the extra space earn a $0.15 performance credit per dollar, designed to offset up to 100% of the fee, but the fee is owed whether or not you use the space, and Amazon advises against requesting capacity you are not confident you can sell.

Two details make Capacity Manager a planning tool. Each request carries an expiration date, which Amazon says exists because sellers "may need to commit to procurement or manufacturing decisions." And if the confirmed limit comes in higher than the estimate, you can cancel granted space until the second-to-last day before the limits take effect. The bid mechanics are in our capacity limits playbook.

Peak season tightens this clock. For the 2026 holidays, Amazon's Q4 2026 peak readiness playbook warned that inbound slots would be limited and that "you may see lower estimated capacity limits for October and November." Keep that warning in next year's peak plan.

The AWD Clock: Who Decides the Quantity

AWD moves the quantity decision to Amazon. Once you enroll, SKUs are auto-replenished by default, and you can opt out SKU by SKU, per Amazon's AWD replenishment page, which lists the quantity as decided by Amazon for auto-replenishment and by the seller for manual moves.

Amazon's model sets a target level in FBA from its forecast of demand for the upcoming 52 weeks, with conservative, median and optimistic projections, the weighted average lead time from AWD to FBA, and any minimum or maximum limits you set. It runs seven days a week and triggers a shipment when FBA available plus in-transit units fall at least half a carton below the target.

For the capacity clock, this is the key line. Auto-replenished inventory is exempt from FBA capacity limits, while a manual move "will get rejected if the shipment created would go above the limits." The Q4 2026 playbook repeated it for peak: auto-replenished inventory "isn’t subject to 'FBA capacity limits' during peak."

The trade is time. Amazon says replenishment from AWD to FBA takes "up to an average of 14 days," and adds: "Expect delays in processing during the peak period due to the increased volumes." AWD also moves stock in whole cartons, and the plan has to position it early enough to absorb the transfer.

Fees tie AWD to the rest of the plan. On its AWD fees page, Amazon waives the low-inventory-level fee, the storage utilization surcharge and the aged inventory surcharge for 181 to 365 days on a SKU when 70% or more of it reached FBA through AWD auto-replenishment over the previous 90 days. A maximum limit can bring the first fee back and a minimum can bring the other two back; the ratio math is in our post on the AWD 70 percent rule.

Two AWD dates go on the calendar: Amazon assesses smart storage eligibility on the 25th for the following month's charges, with the status updated by the 28th, and the AWD Fee Metrics report is generated each Wednesday. Since July 31, 2026, AWD only accepts sortable items, smaller than 18 x 14 x 8 inches and under 20 pounds, so larger SKUs go to FBA directly. Stock that reaches FBA through AWD carries no separate inbound placement fee; the full cost comparison is in Amazon AWD vs a 3PL in 2026.

The Supplier and 3PL Clocks: Lead Time and Lunar New Year 2027

Amazon's recommendations are only as good as the lead time you give them. Its SKU settings ask how a product moves: the supplier ships directly to Amazon, ships to your facility and you forward the full shipment, or ships a bulk supply to your facility and you replenish Amazon from there. A brand that holds stock at a 3PL is in the third case, and its settings should say so.

The supplier clock starts long before a shipment to Amazon exists: the purchase order, production, freight and your 3PL's receiving all come first. Our post on MOQ, lead time and the prep center walks through stacking those legs.

For brands that buy from China, one date shapes the next plan. Lunar New Year's Day falls on Saturday, February 6, 2027, per the Hong Kong government's 2027 holiday list and the Hong Kong Observatory's calendar. In mainland China the official schedule comes from the State Council; its 2026 notice, dated November 4, 2025, set a nine-day Spring Festival break, February 15 to 23, 2026.

Treat 2026 as a precedent, not as the 2027 calendar. Get your factory's closing and reopening dates in writing, and place purchase orders early enough for production and freight to finish around them; the reverse calendar is in our Chinese New Year 2027 plan.

The 3PL clock is the one you can shorten. It runs from your freight reaching the 3PL's dock to a shipment reaching Amazon or AWD. Ask your 3PL what its published prep window covers, then plan carrier transit and Amazon's receiving on top of it.

The Monthly Calendar, Built From Amazon's Dates

Put Amazon's dates in one table and the meeting nearly schedules itself. Every row comes from an Amazon help page; the grouping is mine.

Here is the rhythm I would run against that table. It is my recommendation, not an Amazon rule.

• Week 1, the finance close. Book last month's Amazon charges as they land, and reconcile units between your 3PL, the Amazon ledgers and your own records, as in our three-way reconciliation guide.
• By the 14th, aging decisions. Submit any removal order before 11:59 p.m. Pacific time, ahead of the snapshot on the 15th.
• Week 3, the demand review. Download Amazon's 26-week forecast, set it next to yours, agree on one number per SKU, and check AWD ratios and limits before the 25th.
• Week 4, the decision meeting. When capacity limits land, lock next month's inbound plan, request extra capacity for the estimated months only for stock you expect to sell through it, and release purchase orders.

"My advice: build the monthly plan around the clocks you don't control. Amazon confirms your FBA capacity one month at a time, an AWD-to-FBA transfer takes up to an average of 14 days, and Lunar New Year falls on February 6, 2027. Demand is only one of the numbers in that meeting."

Bernardo Campelo, Founder of PrepVia

The Agenda and Who Decides What

Keep the agenda to decisions that change next month's inventory position: Amazon's restock quantities and ship-by dates, next month's capacity and the two estimates, FBA historical days of supply, over 30 and 90 days, against the 28-day line of the low-inventory-level fee, AWD ratios and limits, launches, purchase orders and cash. The table shows who owns each call, based on Amazon's pages.

Launches need their own line. Under the New Selection Program 2026, an eligible branded parent ASIN that is new to FBA gets free storage and no low-inventory-level fee or storage utilization surcharge on its first 200 units for 120 days from its first FBA inbound date. On October 28, 2026, Amazon extended enrollment to March 31, 2027. Amazon shows no forecast for products without sales or for new ASINs with limited history, and newly created ASINs do not affect your IPI score in their first 90 days.

There is a new row to decide. At Accelerate 2026, Amazon said sellers can let Seller Assistant "monitor and execute tasks like restocking and pricing on your behalf," adding: "Choose whether it recommends or acts, and every action is logged." About Amazon also announced supply chain capabilities, "starting with agents for aged inventory and inbound planning." Decide which tasks the assistant may execute and which it may only recommend; the announcements are in Accelerate 2026 for operators.

Closing the Plan With Finance

The finance half of S&OP turns the inventory plan into charges and cash. Four charges matter most for a year-end plan, all at Amazon's 2026 rates.

• Peak storage. For non-dangerous goods, standard-size FBA storage costs $0.78 per cubic foot per month from January to September and $2.40 from October to December, before any storage utilization surcharge; oversize goes from $0.56 to $1.40.
• Holiday peak fulfillment fees. They apply from October 15, 2026 to January 14, 2027. In its Holiday 2026 announcement, Amazon said the increase averages $0.32 per unit, with the 3.5% fuel and logistics surcharge on top.
• Aged inventory. The surcharge starts at 181 days in a fulfillment center, and at 271 days for clothing, shoes, bags, jewelry and watches.
• Low inventory. The low-inventory-level fee applies only when both the 30-day and 90-day historical days of supply sit below 28 days, measured per FNSKU.

The squeeze between the low-inventory fee and the storage charges is where the plan earns its keep. When a capacity limit keeps you from restocking a low item, Amazon's advice is to "reduce excess inventory" elsewhere; the fee tables are in our posts on the low-inventory-level fee and Q4 peak storage.

Timing matters as much as rates. Placement fees, reservation fees and storage all land after the month that caused them, so the meeting hands finance the dates and your accountant decides how to book them.

Cash runs on its own clock. Amazon's standard delivery date reserve holds funds until seven days after delivery: in Amazon's own example, an item sold on January 1 and delivered on January 6 becomes available for disbursement starting January 14, and Amazon can extend the period based on risk and performance. The cash side is in Amazon FBA cash flow in the DD+7 era. When Amazon publishes fee changes, re-price the plan before you lock the annual budget.

Where a 3PL Fits in the Calendar

A 3PL sits on two of the four clocks. It holds the stock that FBA and AWD cannot take yet, and its dock time is part of the lead time for every unit that passes through it. It does not set your capacity limit, decide AWD's quantities or see your Amazon forecast unless you share it. Before you build the calendar, ask your 3PL for four things in writing:

• A published prep window. What the clock covers and when it starts, so you can plan carrier transit to Amazon on top of it.
• On-hand by SKU. A count you can set next to Amazon's FBA and AWD numbers at the monthly close.
• Discrepancy reporting. How fast short or damaged cartons are reported, and with what proof.
• Storage terms. How storage is billed, so stock held outside FBA has a known cost.

At PrepVia, our standard prep window is 24-36 hours, and FastLane 35H is 35 hours end to end, from check-in at PrepVia to Amazon FBA delivered status, or the prep is free. Discrepancies are reported within 24 hours of arrival, with photos, and storage is billed daily, on the space used. We receive imported freight at 8507 NW 72nd St, Miami, FL 33166 and route it into Amazon FBA, including on Amazon partnered LTL and FTL.

The PrepVia app includes profit per product, sales trends with a forecast, and restock planning with suppliers and purchase orders. Pricing is quoted per account on a free 15-minute call, and Net-30 is available.

Frequently Asked Questions

What is S&OP for an Amazon brand?

A monthly meeting that agrees on one demand number and one supply plan per SKU, then checks it against Amazon's limits and your cash. It reconciles Amazon's demand forecast, the monthly FBA capacity limit, AWD's automatic replenishment and the lead time from your supplier through your 3PL.

How far ahead does Amazon forecast demand for my products?

Up to 40 weeks in Amazon's demand forecast tool, with a downloadable 26-week file that refreshes weekly. Amazon calls it a planning tool, not a guarantee, and shows it only for products with sales.

When does Amazon announce FBA capacity limits?

Typically during the fourth week of the month, when Amazon confirms the coming month, adjusts the estimate for the next one and estimates the third. Extra space can be requested in Capacity Manager for future periods only.

Does AWD inventory count against my FBA capacity limit?

Inventory that AWD auto-replenishes into FBA is exempt. Manual moves from AWD are subject to the limit and are rejected if they would exceed it, and Amazon says AWD-to-FBA transfers take up to an average of 14 days.

When is Lunar New Year 2027?

Saturday, February 6, 2027. China's official holiday schedule comes from the State Council, whose 2026 notice set a nine-day break, so get your factory's own dates in writing and place purchase orders early.

What does DD+7 mean for the plan?

Amazon's standard reserve holds sales funds until seven days after delivery, and Amazon can extend that period. The finance close should plan cash on delivery dates, not order dates.

Final Take

Inventory forecasting on Amazon is less about predicting one number and more about timing decisions against clocks you do not control. Amazon publishes those clocks: a forecast it calls a planning tool, a capacity limit that typically lands in the fourth week, an AWD model that sets its own quantities, and a charge date for every fee.

Put them in one calendar, add the supplier and the 3PL, and book the decision meeting for the week your capacity limits arrive. Download Amazon's 26-week forecast before that meeting, and bring your supplier's Lunar New Year dates in writing.