Amazon restock limits are among the most misunderstood aspects of selling through FBA. Many sellers believe they are tied to IPI. Others assume that selling more automatically unlocks unlimited space. The truth is none of these assumptions is fully correct.
If you send inventory to FBA, Amazon restock limits directly control how much product you can ship and store. They affect your replenishment strategy, your cash flow, your sell-through rate, and even your ranking stability. If misunderstood, you risk leading your business to stockouts and unnecessary storage costs.
We will walk through what Amazon officially defines as restock limits to what actually moves your storage caps, what does not move them, and where field experience suggests additional factors may be at play.
What Are Amazon Restock Limits and How Do They Control FBA Inventory Flow?
Amazon restock limits are unit-based caps that determine the maximum number of units you can send to and store in FBA for each storage type. You see them inside Seller Central, it’s the “Capacity Monitor” button under the FBA Dashboard:
In New Seller Central, you will see the button at the top right corner ofthe FBA inventory section:
It is important to understand that the limits are not set at the ASIN level. They are set at the storage-type level. That means standard-size, oversize, apparel, footwear, aerosol, and flammable types each have their own independent limit.
If you hit your restock limit for standard-size products, you cannot send more standard-size inventory, even if you still have capacity in oversize, for example.
This system replaced the older ASIN-based limit model.
Instead of limiting individual SKUs, Amazon now gives sellers “the flexibility to allocate capacity across products within a storage type”.
What does this mean to the IPI score?
Restock limits apply regardless of your IPI score. They manage inventory inflow and are different from storage volume limits, which measure physical space in cubic feet and are tied to IPI.
How Amazon Calculates Restock Limits
According to Amazon’s official documentation, restock limits are calculated using several inputs:
- Past sales performance
- Forecasted sales
- Seasonal trends
- Overall fulfillment center capacity
Amazon also confirms that Multi-Channel Fulfillment sales are included in the demand data used for calculations.
Forecasting is handled through Amazon’s internal models, which predict expected sales based on historical performance and seasonal behavior.
According to these calculations, you can check out how each SKU is performing from an inventory perspective. There are three statuses:
- Healthy inventory
- Excess inventory
- Low stock
You can quickly see this under the FBA inventory tab:
What Amazon does not tell is how much each factor matters in the calculation. Sellers see the result, but not the formula behind it.
One important clarification from Amazon: IPI does not directly determine restock limits. That means improving IPI alone does not automatically increase your restock capacity.
The algorithm refreshes restock limits regularly.
Related article: Amazon FBA Inbound Placement Service Explained: Costs, Fees, and When It Makes Sense
The Three Core Metrics Inside the Capacity Monitor
After expanding the Capacity Monitor, you will see three core metrics:
- Maximum shipment: The capacity available for you to send shipments to Amazon fulfillment centers.
- Open shipment: The capacity used by your shipments that have not yet been received by Amazon. Statuses: Working, Shipped, In transit, Delivered, Checked in, or Receiving.
- On-hand: The capacity used by your current inventory at Amazon fulfillment centers. It does not include any inventory that is pending removal.
Ideally, you will see your current usage around the 70% mark, with a very healthy bandwidth to allocate more inventory, create new listings, and improve conversions.
However, this isn’t always the case. Let’s look at what happens when you exceed Amazon’s limits:
As you can see on the chart on the right side, Amazon’s FBA capacity limit for February is 121.28 cubic feet. The number increases in April, when more sales are projected due to seasonality and other factors.
However, on-hand inventory is exceeding this limit by a whopping 35.07%. More importantly, it’s about 1,075 estimated units occupying 41.38 extra cubic feet of Amazon’s FBA distribution centers:
When Amazon’s restock limits are exceeded at this level, the platform won’t let you send more units until the issue is resolved. Period. This is a poor situation to get yourself in, especially if you’re selling products affected by seasonality or if you have more shipments planned for the quarter.
The solution
How can you solve this situation? Well, usually there is a set of practices you can do as soon as possible. Of course, the main objective is to reduce on-hand inventory so you can continue sending more units. And you do that by increasing sales fast, even at the expense of some of the profit:
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- Post outlet deals to feature discounted products and help you move excess FBA inventory. These deals are specifically designed for overstocked items, slow-moving inventory and products at risk of long-term storage fees.
- Lower the list price of your excess inventory to increase conversion rate. Higher conversion leads to faster sell-through. Faster sell-through reduces excess inventory and aged units.
- Running additional Advertising campaigns if inventory is sitting but pricing is competitive. Sometimes visibility is the problem.
- Create Brand Tailored Promotions to send special discounts directly to repeat customers, high.spend customers, recent buyers and brand followers.
- Liquidate at a slight loss if you have no other option and need the occupied space now.
After taking these measures, there are additional practices to prevent this situation from happening again. We’ll see more on that later.
At the end, you should aim to have your capacity monitor looking like this:
What Actually Increases Restock Limits
Amazon confirms that restock limits are influenced by historical and forecasted sales. In practical terms, this means sell-through matters.
When inventory moves quickly and consistently, demand forecasting improves. Higher projected demand can support higher restock limits over time.
- Increasing sales velocity is the most reliable official method to increase restock levels.
This is not a surprise. All of Amazon’s systems are geared toward benefiting sellers who sell more units at the lowest possible rate. If you’re constantly selling your three-month inventory right when the clock is ticking, then it’s only logical that Amazon will increase your restock levels so you can sell even more. They benefit from it. You benefit from it.
Reducing excess inventory also increases your available shipment quantity, though it does not directly increase your limits. It helps, but it’s not the same.
What Does Not Increase Restock Limits
As we mentioned earlier, improving IPI does not directly increase restock limits. Amazon clearly separates restock limits from storage volume limits. Beyond this factor, increasing your supplier order size does not increase restock limits either.
As we saw earlier, sending inventory beyond your limit is a policy violation and may result in the cancellation of shipments.
You also cannot trade capacity between storage types. If you have unused oversize capacity, it cannot be applied to standard-size.
Does Inventory Age Impact Amazon Restock Limits?
Yes. Inventory age has a direct and meaningful impact on restock limits.
When inventory sits in Amazon’s fulfillment centers without selling, it occupies warehouse space without generating revenue. Amazon is not designed to function as long-term storage network. When units remain unsold for extended periods, they reduce operational efficiency and increase carrying costs.
Inventory becomes officially categorized as aged once it exceeds 180 days. Amazon breaks aged inventory into three main tiers:
- 180 to 270 days
- 270 to 360 days
- 365+ days
Once inventory passes 180 days, Amazon applies per-unit, per-day surcharges. The older the inventory, the higher the penalty. This creates a financial burden on sellers.
In plain terms, you should expect to keep 3 months of supply at Amazon, and no more. This window, combined with the delays and incredibly high pricing we’re seeing in air and sea freight, definitely makes inventory planning more challenging.
The Inventory Age & Excess dashboard
The Inventory Age & Excess dashboard in Seller Central provides a clear view into this issue. At the top, you can see:
- Total Aging Inventory (181+ days)
- SKUs with Estimated Excess Units
- Estimated Excess Units
In this example, there are 1,279 units aged 181+ days. That means over a thousand units are already in penalty territory.
Even more important is the “Estimated Excess Units” figure, which shows 5,828 units. Excess inventory is inventory that Amazon predicts will not sell within a healthy time frame based on recent demand.
The trend graph below shows how inventory is distributed across age buckets. The darker red segments represent the oldest tiers. These are the units most at risk of long-term fees and restock restrictions
On the right side, the summary compares aging inventory across dates. A reduction from 5,132 units to 1,279 units aged 181+ days shows a 75 percent improvement. This type of reduction strengthens your inventory profile and supports healthier restock behavior.
How to Use IPI Metrics To Avoid Restock Limit Issues
Amazon states that IPI does not directly impact restock limits. That is correct. Your score alone does not raise or lower your restock limits.
But IPI is still a strong indicator of overall inventory health.
All inventory issues are interconnected. Excess units, aged inventory, poor sell-through, and stockouts all hurt your IPI score. At the same time, those same issues weaken your demand signals and reduce operational efficiency inside Amazon’s network.
A poor IPI score can also lead Amazon to reduce your total storage space. While that is a different system from restock limits, it still reduces flexibility and increases pressure on your inventory planning. 
A high IPI score reflect strong inventory balance. Low excess. Healthy sell-through. Stable in-stock rate. No stranded inventory. This kind of management supports predictable restock behavior. And makes increasing sales velocity much easier when the demand finally arrives, ultimately leading to higher restock limits.
Conclusion
You do not increase your limits by improving IPI alone. You do not increase them by ordering more units. And you cannot bypass them by shifting capacity between storage types.
What actually protects and grows your restock capacity is simple: consistent sell-through, controlled inventory levels, and disciplined forecasting. Do that consistently, and restock limits stop being a problem.
Advanced FAQs: Amazon Restock Limits, Capacity, and Inventory Strategy
Are Amazon restock limits tied to IPI?
No. Amazon restock limits are not directly tied to IPI. They are driven by demand forecasting, sales velocity, and fulfillment center capacity.
That said, IPI still matters indirectly. A low IPI score usually signals excess inventory, poor sell-through, or stranded units. Those same issues weaken demand signals and reduce your effective capacity over time. Improving IPI alone will not increase restock limits, but fixing the underlying inventory issues often will.
If I sell more, will my restock limits automatically increase?
Not automatically. Increased sales improve Amazon’s demand forecast, which can lead to higher restock limits over time, but there is no immediate or guaranteed increase.
Consistency matters more than short-term spikes. Temporary lifts from promotions or heavy discounting may not meaningfully impact your limits unless demand remains steady. Amazon prioritizes predictable, repeatable sales patterns when allocating capacity.
How often are restock limits updated?
Restock limits are updated regularly, but Amazon does not publish a fixed schedule.
In practice, updates often follow changes in sales velocity, inventory levels, and seasonality. Sellers may see adjustments weekly or more frequently during peak periods. Watching trends over time is more useful than reacting to individual updates.
What happens if I exceed my restock limit?
Amazon will block or cancel shipments that exceed your available capacity.
More importantly, exceeding limits creates operational risk. When inventory is already high and not selling, it prevents you from sending in faster-moving products. This often leads to a mix of excess inventory and stockouts across your catalog.
Can I transfer unused capacity from one storage type to another?
No. Restock limits are set independently by storage type and cannot be transferred.
Unused capacity in oversize, apparel, or other categories does not help if your standard-size limit is maxed out. Capacity planning needs to happen within each storage type, not across your entire catalog.
How much inventory should I keep in FBA?
Most brands should aim to keep one to three months of inventory inside FBA.
Less than that increases the risk of stockouts. More than that increases the risk of aging inventory, storage fees, and reduced flexibility. The right level depends on lead times and demand variability, but the goal is consistent sell-through without overstocking.
Why are my restock limits decreasing even though my sales are stable?
Stable sales alone are not enough to maintain or grow restock limits.
If inventory levels are increasing faster than sell-through, or if more units are aging, Amazon may reduce your effective capacity. The system prioritizes efficiency. If products sit longer in fulfillment centers, your ability to send new inventory can shrink even if revenue stays flat.
Does aged inventory reduce my restock limits?
Yes. Aged inventory has a direct impact on how Amazon allocates capacity.
Inventory that sits beyond 180 days signals low efficiency. These units take up space without generating revenue, which limits your ability to send in new inventory. Clearing aged inventory often improves available capacity faster than increasing sales alone.
Can running ads increase my restock limits?
Not directly, but it can contribute.
Advertising increases visibility and can improve sales velocity. If that leads to consistent sell-through, Amazon’s demand forecast improves, which can support higher restock limits over time. Ads only help if they convert into sustained demand.
Why do I still have capacity but cannot send more inventory?
This usually happens when your capacity is already allocated.
Inventory that is on-hand or tied up in open shipments reduces your available shipment quantity. Even if your total capacity looks high, your usable capacity may be limited. The key metric to monitor is available shipment capacity, not total capacity.
What is the fastest way to free up restock capacity?
The fastest way is to increase sell-through on your current inventory.
This can be done by adjusting pricing, running promotions, launching outlet deals, or increasing visibility through advertising. In some cases, removing or liquidating slow-moving inventory is necessary to immediately free up space and regain flexibility.
Turn Restock Limits Into a Growth Lever
Most brands assume they need more space. In reality, they need better control.
Restock limits are not random. They reflect how your inventory moves, how your demand is forecasted, and how efficiently your catalog performs inside Amazon.
If shipments are getting blocked, inventory is aging past 180 days, or you are constantly adjusting replenishment plans, the issue is not the limit itself. It is the system behind it.
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