Using a Prep and Transfer Warehouse as a Buffer for FBA Replenishment
A container is a clumsy way to restock a listing that sells a steady amount every day. It arrives all at once, it was ordered long before you knew what demand would look like, and it usually holds more than you want sitting in Amazon's network and less than you need if sales jump.
A transfer warehouse turns that one large decision into two smaller ones: how much to bring into the country, and how much to send to Amazon this week. The second decision is made close to the sale, with better information. That's the whole idea of the buffer.
What actually changes
The container goes to the transfer warehouse instead of straight to Amazon. Cartons are received, counted and stored. When a SKU runs low at Amazon, the warehouse sends a smaller shipment against a shipment plan.
You get a few practical things out of this:
Control over how much sits at Amazon. Storage fees and inventory limits change, so check Amazon's current rules, but holding your reserve elsewhere gives you room to respond when they do.
A place to catch problems. A missing unit label or an oversized carton is a small job on a warehouse table. It's a much bigger job after the shipment has been rejected or delayed.
Room for bad weeks. A late supplier or a slow check-in hurts less when there's stock one short truck ride behind the listing.
Options. Stock that hasn't gone to Amazon can still go to another channel.
What it costs you
It isn't free, and it isn't always worth doing. You add a second handling step, another freight leg, storage, and one more point where two counts can disagree. If your product sells predictably, your cartons arrive ready for Amazon, and you rarely run out, shipping direct may well be cheaper.
The buffer earns its cost when running out of stock or overstocking at Amazon costs you more than the extra handling does. To judge that, look at what your last stockout did to sales and ranking, and what your slowest SKUs are paying to sit in Amazon's warehouses.
Three things to work out by SKU
Transfer lead time. Count from the day you decide to send stock to the day those units are available for sale. That includes warehouse handling, freight and Amazon's check-in. Measure your own shipments rather than guessing.
Daily sales. Use recent sales, not last year's average.
Safety days. This is how wrong the first two numbers tend to be.
The send trigger is simple: lead time plus safety days, multiplied by daily sales. When available plus inbound units at Amazon fall below that number, send more.
Here is a hypothetical, with figures invented only to show the arithmetic. A SKU sells 20 units a day, the transfer lead time is 12 days, and you want 5 safety days. Seventeen days times 20 is 340 units, so that's your trigger. Run the same sum with your ocean lead time to decide when to reorder from the factory.
Where it goes wrong on the floor
Labels printed too early. Carton labels belong to a specific shipment plan, so a factory can't print them months ahead. Decide who prints what and when. Unit labels can go on at the factory, but only if someone has checked they scan.
Mixed cartons. A carton with three SKUs has to be opened and sorted before it can go anywhere. Ask your factory for single-SKU cartons where you can.
Assuming location solves placement. Amazon decides where inbound shipments go, and a plan can be split across several sites. Being near one fulfillment center only helps when that center is the one assigned. Check the current inbound placement rules before building a plan around any one site.
No paper trail. When Amazon's receipt doesn't match what left the warehouse, you need carton counts, weights and proof of delivery to reconcile it. Ask what the warehouse records for each outbound shipment before the first one leaves.
Online arbitrage sellers have the same problems on a smaller scale. Units arrive from many stores, in small lots, and each one has to be checked and labeled. Check Amazon's current requirements on sourcing documents too, and keep your invoices.
A location worth checking
Tengloong Warehouse has a 1,000-square-meter e-commerce warehouse in the 91761 area of Southern California, about a 15-minute drive from Amazon's ONT8, and commits to completing inbound receiving within 48 hours. Services include FBA transfer and allocation, labeling and relabeling, and support for Amazon OA sellers. If you're deciding whether a buffer fits your SKUs, send your questions through the contact page.