3PL vs 4PL vs Fulfillment Center vs Public Warehouse

People use these four words for the same building all the time, and a prospect who says "we need a fulfillment center" may really want a public warehouse. Getting the term right early saves a quote that misses the point.

The short version: stock belongs to the client in all four cases. What changes is how much the provider does, how much it decides, and what it charges for.

3PL (third party logistics provider)

A 3PL does logistics work for another company: storing goods, picking and packing orders, receiving, labelling, returns, sometimes transport. The "third party" is the provider; the first two are the seller and the buyer.

A 3PL usually runs its own building, its own people and its own systems. The client sends stock in and orders through, and the 3PL does the work. The client sets the rules (how to pack, which carrier, what counts as late), the 3PL carries them out, and both sides argue about it at the monthly review.

The term is broad. A warehouse that only stores pallets, a parcel shipper and a firm that runs a client's whole distribution network might all call themselves 3PLs. This site is about the first and the second kind, and about the software they run on. For the role that runs one of these buildings, see what a 3PL manager does.

4PL (fourth party logistics provider)

A 4PL sits above the warehouse. It manages a client's supply chain on the client's behalf: choosing carriers and warehouses, setting up the processes, watching performance and fixing problems. It often does this by hiring and directing several 3PLs.

The practical differences are:

• a 4PL usually owns no warehouse or trucks of its own;
• it makes decisions about the client's network, where a 3PL carries out tasks inside it;
• it is paid for managing and improving the chain, not for each pallet or order handled.

If you run a warehouse, you are far more likely to work for a 4PL, as one of its 3PLs, than to be one. When that happens, the 4PL's instructions arrive through a layer, and your system needs to show the right inbound notice and the right client name on the right stock.

Fulfillment center

A fulfillment center takes orders, usually many small ones, and ships them. It is built around picking, packing, parcel labels and returns, mainly for online sellers.

Most fulfillment centers are 3PLs. Not every 3PL is a fulfillment center, though. A firm that only stores pallets for a distributor and ships full pallets on request is a 3PL, and it would struggle with fifty parcels an hour.

Fulfillment centers are typically paid per order and per item, plus storage. That is why per-order pricing questions come up so often with them.

Public warehouse

A public warehouse rents space and basic services to whoever needs them. Think of a self-service arrangement with staff: the customer brings pallets, the warehouse stores them, and it handles them when told to.

The customer often does the planning, such as sending outbound instructions and booking carriers. The warehouse provides racks, labour and a dock. Charges are usually for storage, in and out handling, and extras on request.

"Public" here means open to the public, not government owned. It is the opposite of a private warehouse, which one company runs for its own goods.

Side by side

The last row is a pattern, not a rule. Agreements vary, and you should read the contract, not the label.

Why it matters for your system

The terms change what a warehouse system has to do.

• Whose stock is it? In every case the stock belongs to someone else, so every record needs a client against it, and every report needs to separate clients.
• Who tells you what is coming? With a 4PL in the middle, the advance notice may come from the 4PL, not the brand, and discrepancies may need to go to both.
• What do you bill? A fulfillment center needs per-order and per-item charges. A public warehouse needs storage and in and out handling. The same system has to handle both if you offer both.
• How is it used? Order fulfillment needs batch picking and parcel labels. Pallet storage needs location control and pallet moves.

If you are working out which kind of system fits your type of operation, what kind of WMS a 3PL should get goes through that.

Which one do you need as a client?

A rough guide, in plain terms:

• You sell online and ship many parcels: a fulfillment center, which will usually be a 3PL.
• You have pallets to store and ship now and then, and you have your own planners: a public warehouse.
• You want someone to run the warehouse and also take work off your team, such as returns and kitting: a 3PL.
• You have several warehouses, carriers and regions and no one to manage them: a 4PL may be worth discussing.

If a provider will not tell you which of these they are, ask who decides when an order is late, who owns the stock record, and what happens when stock does not match.

Questions people ask

What is the difference between a 3PL and a 4PL?

A 3PL runs warehousing, transport or fulfillment tasks for a client. A 4PL manages the client's whole supply chain, often by choosing and directing several 3PLs, and usually owns no warehouse itself.

Is a fulfillment center the same as a 3PL?

A fulfillment center is one kind of 3PL service, focused on picking, packing and shipping orders. Many 3PLs also store pallets, cross-dock and manage freight, which a fulfillment center may not.

What is a public warehouse?

A public warehouse rents space and basic handling to any customer, often by the pallet and by the month. The customer usually decides what to do with the stock and the warehouse follows instructions.

Who owns the inventory in a 3PL?

The client owns it. The 3PL holds it and handles it, so every record has to say whose stock it is.