How to Send Inventory to a Prep Center: A Seller's Checklist

Before you send inventory to a prep center, do the boring part first

Most receiving headaches we see on the dock started weeks earlier, at the supplier's warehouse, when nobody wrote anything down. So if you're figuring out how to send inventory to a prep center for the first time, the honest answer is that the shipping part is easy. The setup is where it goes right or wrong.

This guide walks through it in order: onboarding, what to tell your supplier, carton labels, paperwork, pallets versus parcels, and the stuff that causes delays when it shows up. It's written from the receiving side of a warehouse in Niles, Illinois, so it's practical, not theoretical.

Not sure a prep center is even the right fit yet? Start with what an FBA prep center actually does and come back.

Step one: onboarding comes before freight

Here's the rule at Treasure World Prep Center, and plenty of other warehouses work the same way: don't ship anything until verification and onboarding approval are done and your inbound instructions are confirmed. A box that arrives for an account nobody has set up is a box with nowhere to go.

For onboarding we ask for accurate, verifiable U.S. company information:

• Legal company name and business address
• EIN or business registration
• An authorized U.S.-based signer
• A valid government photo ID

After that, the work order gets confirmed. That means handling, packaging, storage and destination are defined before inventory is sent. Do the units need FNSKU labels? Poly bags? Are they staying in storage or going straight out to Amazon? Settle it now, not when the pallet is already sitting on the floor.

Also check the product list against what the warehouse accepts. We don't take hazardous materials, chemicals, canned soda, or leaking or unsafe products, and liquids over 2 lb need prior written approval. Dietary supplements need invoices from a U.S.-based manufacturer or authorized U.S. distributor. Better to find out before your supplier ships.

What to tell your supplier

Suppliers ship hundreds of orders a week. Yours is one of them. Clear supplier shipping instructions are the single biggest thing you control, so put them in writing and keep them short. One page is plenty.

1. 01

   The exact ship-to address

   Use the full address and any reference line the warehouse gives you during onboarding. Don't paraphrase it.

2. 02

   Your company name on every carton

   The warehouse needs to know whose freight it is the second it comes off the truck. A box with only the supplier's name on it is a mystery box.

3. 03

   One SKU per carton when possible

   Mixed cartons are sometimes unavoidable. When they happen, the carton should say what's inside and how many of each.

4. 04

   A packing list in or on the shipment

   Plus a copy emailed to you, so you can forward it before the freight arrives.

5. 05

   Tracking or a BOL number as soon as it ships

   Parcels need tracking numbers. Freight needs the bill of lading and an expected delivery window.

If you buy from overseas, ask your freight forwarder the same questions. The forwarder's paperwork is often what actually reaches the dock.

Carton labeling that makes receiving fast

None of this is fancy. It just needs to answer three questions from across the room: whose is this, what's in it, and how many.

• Your company or account name, large and on at least one side
• SKU (and ASIN or other marketplace ID if you have it)
• Units per carton
• Carton number, like 3 of 12, so a missing box is obvious

Don't confuse these with marketplace labels. FNSKU labels on the units and carton labels for Amazon are part of prep, and the prep center can apply them for you (we charge $0.35 to $0.40 a unit for FNSKU labels you supply digitally, and $0.20 for an additional carton label). Your supplier's job is just to make the box identifiable.

The packing list or ASN: send it ahead

Think of it as the shipment's ID card. An advance ship notice (or a simple packing list, honestly a spreadsheet works) tells the receiving team what to expect: SKUs, quantities, carton count, and how it's arriving.

When that list is in hand before the truck, receiving is a count-in. When it isn't, receiving turns into detective work. Which brand is this? Is 11 cartons right, or should it be 12? Nobody knows, so everything waits for an answer from you.

At our warehouse, standard labeled cartons are received at $1.00 a carton with a basic count-in. If you want an exact each-count, unit count and carton verification is $5 a carton plus $0.10 a unit. Our inbound receiving and inventory control page lists the rest, like lot and expiry capture.

Pallets vs. parcels

Small shipments (a few to a few dozen cartons) usually come by parcel carrier. Bigger ones come palletized on a freight truck. Both work. They just get handled differently.

Parcels

Every box travels on its own, so every box needs its own label and its own tracking number. Send the full tracking list, not just the first one. Boxes from the same order can arrive across two or three days, and that's normal.

Pallets

Ask the supplier to keep one SKU per pallet where possible, wrap it properly, and label the pallet itself, not just the cartons inside. Pallet receiving is $10 a pallet here. And if the freight shows up floor-loaded in a container instead of on pallets, that's a separate unload job, so mention it when you request the work order.

What causes problem receiving

Every warehouse has a version of this list. Ours treats these as unscheduled or problem receiving, which is billed at standard labor rates ($40 an hour) instead of the per-carton rate:

• No ASN or packing list
• Mixed SKUs in cartons with nothing marked
• Boxes with no labels or no company name
• Damaged freight that needs documenting
• Counts that don't match and need a recount

None of these are disasters. They just cost time and money that a five-minute email to the supplier would have saved. Evidence photos come with it too (first three free, then $1 each), which is useful when a supplier shorts you.

Once the inventory is in clean, the actual prep goes quickly. If Amazon is the destination, our Amazon FBA prep service picks up from there, and 24-hour prep is available for qualifying work orders.

A quick pre-ship checklist

Print it, tape it next to your monitor, whatever. Before your next inbound shipment leaves the supplier:

• Onboarding approved and inbound instructions confirmed
• Work order agreed: prep, packaging, storage, destination
• Products checked against the prohibited list
• Supplier has the written instructions
• Packing list or ASN forwarded to the warehouse
• Tracking numbers or BOL shared

That's it. Six lines. Every time you send inventory to a prep center, the same six lines apply, whether it's 40 units or a full truck. Rates for receiving, prep and storage are all on our pricing page. If you want to walk through your first shipment with us, request a quote and tell us what's coming, how much, and from where.