A restock decision answers one question: how many units do you need to order, and when, so sellable stock arrives before you run out? No forecast makes future demand certain. A good one starts from records you can check and writes down every assumption, so the next review can see what changed.
This page covers the inputs, a simple way to turn them into an order, and how to keep the plan honest after the order goes in.
Start with clean sales history
Export sales for one marketplace and one reporting period at a time. Amazon.ca and Amazon.com should stay separate, because demand, pricing and fees differ.
Then mark the periods that don't reflect normal demand:
- Days the listing was out of stock, suppressed or inactive.
- Promotions, deals and coupons.
- Unusual bulk orders.
- Price changes and periods when another seller held the Buy Box.
Sales during a stockout show zero, but demand wasn't zero. If you average those days in, the forecast comes out too low, and the next stockout comes sooner. Note the gap and use the in-stock days to estimate the daily rate.
Keep known future events separate from observed history. A planned promotion belongs in the plan as an assumption, with its status and who confirmed it. Don't blend it into past sales as if it had already happened.
Know your real stock position
"How much stock do we have?" has several answers. Amazon's inventory reports separate units into states, and they aren't interchangeable:
- Fulfillable: units ready to ship to customers.
- Inbound: units in a shipment you've created, shipped or that Amazon is receiving.
- Reserved: units held for customer orders, moving between fulfilment centres or being processed.
- Unfulfillable: damaged, defective or expired units that can't be sold.
Record the date of each report. Amazon notes that its inventory reports are snapshots, so a number can be out of date by the time you read it.
Add the stock that isn't at Amazon yet: units at your warehouse, units at a prep centre and units your supplier has confirmed but not shipped. Mark which of these have documents behind them and which are still estimates. A supplier shipment isn't stock that customers can buy.
For supplements and other expiry-dated products, record expiry lots too. A large total can hide a shortage of usable stock if much of it expires soon.
Collect supply facts, with dates
Lead time is usually the weakest input, because it changes and old numbers stick around. For each product, record:
- Supplier production time, as confirmed for this order.
- Transit time by the shipping method you'll actually use.
- Prep and labelling time.
- Amazon receiving time, from delivery to fulfillable.
- Minimum order quantity and case pack.
- The date each figure was confirmed, and by whom.
Don't carry last quarter's lead time into this quarter's order without checking it. Mark the date on every supplier confirmation.
Turn the inputs into an order
A simple method works for most catalogues, and it's easy to explain:
- Daily rate. Average units sold per in-stock day over a recent, normal period.
- Lead-time demand. Daily rate times total lead time, from placing the order to stock becoming fulfillable.
- Safety stock. A buffer for slower supply or faster sales. Set it by product, based on how much demand and lead time have actually varied for you.
- Reorder point. Lead-time demand plus safety stock. When available and inbound stock falls to this level, it's time to order.
- Order quantity. Enough to cover the period until the next order, rounded to case packs and minimums, and checked against expiry and storage limits.
Amazon's Restock Inventory tool gives its own suggestions. Treat them as a second opinion. Check them against your records before copying a number into a purchase order.
For more on buffers for expiry-dated products, see reorder points for supplements on Amazon.
Check the constraints before you send
A correct quantity can still fail in practice. Before the order is final, check:
- FBA capacity limits. Amazon limits how much you can send. A shipment you can't create doesn't help.
- Storage costs and aged stock. Ordering far ahead adds monthly storage, and units held too long can attract aged inventory surcharges.
- Expiry. Supplements are treated as expiry-dated by FBA. Units close to expiry can be removed for disposal, so a large order of a slow seller can turn into waste.
- Cash. The order has to make sense for the business, not just the stock plan.
Keep a decision record
Write down the quantity a person proposes, the inputs used and the open questions. Keep the proposed quantity, the supplier's confirmation and the units eventually received as separate figures.
Save the worksheet with the purchase order. At the next review, compare what was planned with what arrived and sold. That shows whether a supplier commitment changed, a promotion didn't run or a report didn't match, without rewriting the original decision after the fact.
Use an exception list between reviews
Between restock reviews, a short exception list catches problems early. Each item names a product, a documented condition and a person responsible. Useful exceptions include:
- Available stock differs from the last reconciled figure.
- A shipment's status in Seller Central doesn't match the carrier or receiving documents.
- A supplier changes a production, prep or delivery date.
- Stock can't be sold because of condition, expiry or listing status.
Record the marketplace, SKU, report time and source next to each one. Investigate a difference against orders and movements before treating it as an error. Keep the item open until a record explains it and someone has written down the next step.
When to revisit the plan
Review the plan on a fixed schedule, and also when something material changes:
- Sales move well above or below the daily rate.
- A supplier date slips.
- A listing goes inactive or loses the Buy Box.
- A promotion is added or cancelled.
Planning stays useful when uncertainty is written down rather than hidden behind a precise-looking date. A stockout hurts more than a late plan, and recovering from one takes time.
How we handle this
Restock planning is part of our weekly inventory and replenishment work. You get a dated replenishment plan with the stock position and assumptions behind it.
Want to see where your products stand today? Get a free Amazon check. It covers who's selling your products, who holds the Buy Box, price and stock, and the three things we'd fix first.