Amazon now applies monthly capacity limits measured in cubic feet, replacing the old weekly restock caps. Check Capacity Monitor in Seller Central now to see your current limit and utilisation by storage type. Short-term levers such as Capacity Manager reservations and Amazon Warehousing and Distribution can buy you breathing room. However, Capacity Monitor is the authoritative number for what you can actually ship this month.
TL;DR:
- Capacity Monitor shows a separate monthly cubic foot limit for each storage type, while on hand inventory and every open shipment consume that allowance.
- An open shipment counts when created, so wait for the monthly update before relying on a higher estimate for next month.
- Capacity Manager reservations and Amazon Warehousing and Distribution cover temporary spikes, but persistently tight limits call for improving sell through and IPI, not recurring fees.
- Subtract on hand inventory and open shipment volume from your current allowance, then divide by average unit volume to estimate how many units fit.
- A product level restriction can block replenishment despite available overall capacity; contact Seller Support with the affected ASIN and shipment details rather than changing packaging.
Table of Contents
- Where to find your capacity limit in Seller Central
- What counts against your capacity and common restrictions
- Five practical levers to create capacity or avoid hitting limits
- How to calculate true headroom before creating shipments
- Automating capacity monitoring to cut restock-limit risk
- Should you pay for capacity or fix your sell-through?
- How Osellpa helps you manage capacity without the spreadsheet
- FAQ
- Sources
Where to find your capacity limit in Seller Central
Go to Inventory, then Inventory Planning, then Capacity Monitor. This is where Amazon shows your current monthly limit, broken down by storage type: standard-size, oversize, apparel, footwear and others, each with its own tab and its own cubic-foot allowance.
Each storage type carries a utilisation bar showing how much of your limit is already used by on-hand stock and open shipments. Below that sits a table of estimated capacity limits for the next few months, which Amazon updates as part of its monthly capacity announcements. These estimates can shift, sometimes sharply, so treat them as planning guidance rather than a guarantee.
Account type changes the picture considerably. Individual selling accounts face a low fixed capacity limit that cannot be raised, while new professional accounts under 39 weeks old often see more conservative limits that loosen as sales history builds, according to seller forum guidance on how capacity works. Established professional sellers with strong sell-through and healthy IPI scores tend to see higher limits and more generous estimates for upcoming months.
Amazon notifies sellers by email and in-platform alerts when limits change, usually tied to the monthly update cycle. Checking Capacity Monitor weekly, rather than waiting for a notification, gives you more warning before a limit tightens around a shipment you were about to create.
What counts against your capacity and common restrictions
Capacity is consumed by two things: inventory already sitting in fulfilment centres and open inbound shipments that haven’t arrived yet, both measured in cubic feet against your storage-type limit. This means stock you’ve shipped but Amazon hasn’t received yet still reserves space against your monthly allowance.
That reservation behaviour catches sellers out constantly. A shipment created today against this month’s limit stays counted even if it won’t land until next month, and forum threads describe sellers who could not create a shipment that technically fit next month’s higher estimated limit because the system enforces the current month’s figure at the point of creation. Timing your shipment creation around the monthly announcement window reduces this friction, since you’re working against the freshest limit rather than a stale one.
Beyond the headline number, individual ASINs can carry their own shipment restrictions: Amazon sometimes blocks replenishment on a specific product regardless of your overall headroom, often linked to minimum inventory level thresholds or performance flags on that listing. When this happens, raising a case through Seller Support with the specific ASIN and shipment details is usually faster than trying to work around it through packaging or quantity changes.
Five practical levers to create capacity or avoid hitting limits
When your utilisation bar is close to the ceiling, a handful of tactics consistently create room, roughly in order of how quickly they take effect.
- Request a Capacity Manager reservation. Specify how much extra capacity you need and a maximum reservation fee you’re willing to pay; Amazon assesses the request and responds within days rather than weeks, but approval depends on demonstrating the sales to justify it.
- Use Amazon Warehousing and Distribution as overflow. AWD stores inventory outside the standard FBA network and releases it into FBA as needed, which is useful as a short-term buffer when your monthly limit is temporarily tight rather than permanently reduced.
- Clear stranded and aged inventory. Run a quick triage on anything flagged as stranded or ageing, create removal orders for low-margin SKUs that aren’t earning their cube, and check for reimbursements on excess inventory you’re removing before it’s written off entirely.
- Reduce cube per unit. Smaller packaging, multi-packs that consolidate several units into one footprint, or palletised shipments can cut the cubic feet a given sales volume consumes, which matters more than unit count because limits are volume-based.
- Control shipment timing. Avoid creating open shipments far ahead of when a carrier will actually move them, and coordinate carrier pickup with fulfilment centre ETAs so you’re not reserving cube for stock that sits in transit longer than necessary.
Pro Tip: Run the removal-and-reservation combination together: clearing aged stock frees cube immediately, while a reservation request covers the gap until that cube shows up in your utilisation bar.
How to calculate true headroom before creating shipments
Before you build a shipment, work out your actual headroom rather than assuming the limit shown is what you can use. The formula is straightforward: available cubic feet, minus on-hand cubic feet, minus open-shipment cubic feet, equals your headroom in cubic feet. Divide that by your average unit cube to get a usable unit count.
Unit cube is simply length times width times height for a single unit, in feet. For multi-SKU shipments, use a weighted average across the SKUs you’re sending rather than a single product’s figure, since mixed cartons rarely match one item’s dimensions exactly.
Treat estimated future-month limits with caution when running this calculation. If next month’s estimate is higher than this month’s, you still can’t create a shipment against it today, as the forum thread on shipment creation limits makes clear, so wait until the limit actually rolls over before committing cube to it.
Automating capacity monitoring to cut restock-limit risk
Checking Capacity Monitor by hand every few days works until you’re managing dozens of SKUs across several storage types, at which point the early warning signs get missed. Automating a handful of signals removes most of that risk.
- Capacity Monitor thresholds: an alert when utilisation crosses a set percentage, before you’re already at the ceiling.
- Open-shipment reconciliation: matching shipments still in transit against what Capacity Monitor shows, so you know your true reserved cube.
- Unit-cube drift per FNSKU: catching when a packaging change quietly increases the cube a product consumes.
- Sell-through alerts: flagging SKUs whose demand is outpacing replenishment before a stockout forces a rushed shipment.
A practical rollout starts with alerts on your top SKUs, then adds unit-cube tracking, then moves to forecast-driven reorder rules once you trust the data. Our inventory management tools and per-FNSKU forecasting are built around exactly this progression, pulling directly from Amazon’s API so you’re not reconciling spreadsheets by hand.
Pro Tip: Start with a three-SKU pilot: set one capacity alert, one sell-through alert and one reconciliation check, then expand once you’ve seen a full monthly cycle.
Should you pay for capacity or fix your sell-through?
Paying for a reservation or AWD buffer makes sense when a short-term spike, not a structural problem, is squeezing your limit, and the margin on the extra units clearly covers the fee. If your limit is tight every month regardless of season, the fix is usually improving sell-through and IPI, not repeatedly paying for overflow.
Peak season rewards early movement, but planning around Amazon’s published peak windows rather than guessing means “early” means weeks, not months (Google Ads Seasonality Adjustments). Shipping too far ahead ties up cube you’ll need later, so plan around Amazon’s published peak windows rather than guessing. Risk-averse sellers should lean on reservations and removals; risk-tolerant sellers can ride tighter margins and bank on sell-through improving before the next monthly update.
— Harry
How Osellpa helps you manage capacity without the spreadsheet
We built our inventory tools to handle the reconciliation work that restock limits now demand: pulling your Capacity Monitor data, open shipments and unit-cube figures into one place instead of three different Seller Central screens. Alerts flag utilisation before it becomes a blocked shipment, forecasting tells you when a SKU is about to outrun its headroom, and automated reconciliation keeps open-shipment cube accurate without manual checking.
- Alerting: threshold-based warnings on capacity utilisation and sell-through.
- Inventory forecasting: per-SKU projections that flag headroom shortages before they bite.
- Unit-cube tracking: catches packaging drift that quietly eats into your limit.
- Automated reconciliation: matches open shipments against Capacity Monitor so your real headroom is always current.
A sensible first step is setting one Capacity Monitor threshold alert and running a 30-day pilot across five of your highest-volume SKUs. From there, our pricing plans scale from Launch at £10 a month up to Advanced at £40 a month, so you can match the tool to the size of your catalogue rather than overpaying from day one.
FAQ
Is Amazon FBA oversaturated?
Competition varies widely by category rather than being uniformly saturated across the marketplace. Capacity limits themselves are a sign Amazon is managing fulfilment centre space tightly, which affects how much any seller, new or established, can scale inventory at once.
How long does it take for Amazon to restock out-of-stock items?
Once a shipment is created and within your current capacity limit, replenishment speed depends on carrier transit time and fulfilment centre check-in, which commonly takes from several days to a couple of weeks. Open shipments reserve cube against your limit the moment they’re created, before the stock physically arrives.
Can I make $1,000 a month selling on Amazon?
Outcomes depend heavily on product margin, advertising spend and how well you manage inventory against capacity constraints, so there’s no fixed answer. Tracking profit per SKU rather than revenue alone is the more reliable way to judge whether a given product line can realistically hit that target.
What is the failure rate of Amazon FBA?
We don’t have a verifiable, sourced figure for this, and it varies enormously by niche, pricing strategy and how well a seller manages inventory and capacity. Sellers who actively monitor Capacity Monitor, sell-through and reimbursements tend to avoid the stock-outs and overage issues that commonly sink newer accounts.
How do I increase my Amazon restock limit?
The main routes are requesting a Capacity Manager reservation, improving sell-through and IPI over time, and reducing cube per unit through packaging changes. None of these are instant, which is why checking Capacity Monitor regularly matters more than waiting for a one-off fix.
