What is a 3PL and when does an ecommerce business need one?

Simply put, a 3PL (third-party logistics) stores your stock and ships your orders.

You send them inventory. They hold it, pick and pack each order, and hand it to a carrier.

That’s a 3PL in a nutshell.

But does your business need one?

The points to evaluate are: when outsourcing fulfillment pays off, what it costs once you get past the headline rate, and how you keep a clear view of your own stock once it’s in someone else’s warehouse.

We’ll work through all three.

What a 3PL does

A 3PL handles the physical work: receiving and storing your stock, then picking, packing, and shipping each order. Most process returns too. 

Many offer extras like kitting or branded packaging, but the core job is getting orders out the door.

You stop paying rent on a warehouse that’s already too small. You stop hiring and training a pick-and-pack team for every peak. You hand carrier relationships to someone who’s shipping enough volume to get rates you won’t.

Where 3PL, 4PL and FBA differ

A 3PL runs the physical fulfillment: your stock, their warehouse, their pickers. 

A 4PL sits a layer above, managing multiple 3PLs and carriers on your behalf, which suits operations that are complex enough that coordinating the logistics is itself a full-time job. 

Fulfillment by Amazon (FBA) is a 3PL with one specialty: it stores your stock in Amazon’s network and fulfills your Amazon orders (and, through Multi-Channel Fulfillment, your off-Amazon orders too).

Most start with one 3PL or FBA, then add a second when they expand into a new region or need a backup for peak. 

The setup itself matters less than the visibility you have across your inventory. That’s where things get interesting.

When does an ecommerce business need one?

In the 2025 Third-Party Logistics Study, 87% of shippers said they’d increased their use of outsourced logistics in the past year, up from 62% the year before.

That’s because, for many retailers, fulfillment is capping growth, not just costing time. 

If you’re turning down a new marketplace or a wholesale order because you can’t physically pack the volume, the constraint has moved from nice-to-fix to revenue-limiting. 

Your peak season will reveal the truth of your needs. If Q4 means hiring temps you’ll train for six weeks and then lose in January, a 3PL absorbs that swing for you. 

Geography is another trigger. Shipping every US order from a single UK warehouse gets slow and expensive fast. A 3PL that can hold stock near your customers cuts both transit time and cost.

If your catalog is diverse and fast-moving, you’ll hit the wall earlier than a single-SKU business. Pick complexity scales with your range. Run the numbers before you commit. The crossover isn’t a fixed order count. It’s when your blended cost per order at a 3PL drops below what you’re spending on rent, labor, and carrier rates now.

What a 3PL costs

A 3PL bills for what it does: receiving and storing your stock, then picking, packing, and shipping each order. Pick-and-pack fees generally start around $0.20 per item. Pallet storage runs $5 to $15 per pallet per month. 

Most charge a one-time onboarding fee, often a few hundred dollars for a smaller business. Returns processing usually lands between $1 and $3.50 per order. Online return rates now sit near 19.3% of sales (NRF’s 2025 Retail Returns Landscape), and returns cost retailers around $30 for every $100 of merchandise sold. 

At roughly one item back for every five you ship, paying a 3PL per return is often cheaper than staffing reverse logistics yourself.

Those are the starting points. From there, variables move 3PL costs: order volume, product size and weight, kitting, climate control, and how much of the carrier discount the 3PL passes back to you. 

Before you take a sales call, run your own numbers. Our guide to how much a 3PL costs breaks down each fee and includes a formula for estimating your real cost per order. Walk in knowing what you spend on fulfillment today, so you can compare a provider’s quote against something concrete.

The visibility gap

There is a cost that never appears on the rate card. The day your stock moves into a 3PL’s warehouse, your record of what’s on the shelf and their record of what’s actually there start to drift. 

A return gets restocked on their side, and your channels don’t hear about it for a day. An inbound shipment lands but isn’t counted immediately. Most oversells don’t happen at peak volume. They happen in the gap between a physical stock movement and your sales channels catching up to it.

You can manage that gap, but only if you can see across it. A 3PL gives you a fulfilment partner. It doesn’t give you a single, current view of stock across that partner, your own warehouse, your FBA, and every channel you sell on. In the Linnworks 2026 State of Commerce Operations report, roughly two-thirds of retailers in both the UK and US acknowledged operating with some level of inventory visibility gap. Only around a third rated their visibility across channels and warehouses as excellent. 

Closing that gap is your job, not theirs.

But won’t the 3PL just handle all of that?

A good 3PL handles its jobs well. 

But it doesn’t reconcile the stock it holds against the stock sitting in FBA and the units still in your own unit. It doesn’t update your eBay and Shopify listings when a batch ships or a return comes back. It doesn’t tell you that the SKU your 3PL is low on is the one you’re about to promote.

That is the tradeoff of the 3PL. You gain capacity and lose direct line of sight. Unless you put something in the middle to hold both views together, you’ve solved a labor problem and created a data one.

Keeping one view when your stock lives elsewhere

The fix is a layer that sits between your channels and your fulfillment, so a sale anywhere updates stock everywhere and routes to the right place to ship. 

Linnworks connects to 3PLs, like ShipBob and CIRRO Fulfillment, as well as Amazon FBA and Multi-Channel Fulfillment, and tracks inventory held at those external centers alongside your own warehouse stock in one dashboard. Orders route to whichever provider should ship them based on rules you set, so adding or switching a 3PL doesn’t mean rebuilding your operation around them.

Hughes Electricals shows why that matters under pressure. The UK appliance retailer, founded in 1921 and selling across Amazon, eBay, and its own sites, runs an in-house 3PL alongside external couriers. During one peak period, a courier buckled under the volume. Because the integrations sat inside Linnworks rather than being hard-wired to one provider, the team brought a replacement courier live in seven days. “Linnworks is the middleware that connects our bespoke ERP system to external channels,” said Henrico Doward, the company’s director. 

Because of Linnworks, outsourcing fulfillment didn’t cost them control of it.

Choosing a provider

When you shortlist 3PLs, weigh both the long- and short-term needs. Ask where their warehouses sit relative to your customers, how they handle returns, what their peak-season track record looks like, and how cleanly their system feeds stock and order data back to yours. A provider that’s cheap per pick but opaque on inventory will cost you the difference back in oversells and support tickets.

If you are planning to outsource your fulfillment, don’t let the transition cost you control. To ensure you keep a unified, live view of your inventory across your own warehouse, 3PL partners, and all sales channels as you scale, speak with the team at Linnworks.

FAQs

What order volume justifies a 3PL?

There’s no fixed threshold, but most 3PLs work best with businesses shipping at least 100 to 500 orders a month, and some set minimums around that range. Below that, the per-order fees and monthly minimums often cost more than fulfilling in-house. The better test is cost per order: when a 3PL’s blended rate drops below what you spend on rent, labor, and carrier fees, the volume is high enough.

What’s the difference between a 3PL and dropshipping?

With a 3PL, you own the inventory and the 3PL stores and ships it for you. With dropshipping, the supplier owns the inventory and ships directly to your customer, so you never hold stock. A 3PL gives you control over product quality, packaging, and stock levels. Dropshipping trades that control for lower upfront cost.

How long does it take to onboard with a 3PL?

Plan for two to six weeks from signing to first shipment. That covers integrating your sales channels with their system, shipping your inventory to their warehouse, and receiving and shelving it on their end. Onboarding before your peak season, not during it, gives you time to catch integration errors while the stakes are low.

Do 3PLs handle returns?

Most do, typically charging between $1 and $3.50 per returned order to receive, inspect, and restock the item. Check how quickly restocked returns show up in the inventory data they feed back to you. A return that sits uncounted for a day is a unit your channels think is out of stock.

Can I use more than one 3PL at the same time?

Yes, and many retailers do once they sell into a second region or want a backup for peak season. The catch is coordination: each provider only sees its own stock, so you need a system that tracks inventory across all of them and routes each order to the right warehouse. Without that, splitting stock across providers multiplies your visibility problem instead of your capacity.