Ecommerce fulfilment: what it is and how to choose a 3PL

Ecommerce fulfilment is everything that happens between a customer clicking "buy" and the parcel arriving at their door: receiving stock, storing it, picking and packing orders, shipping them and handling returns. Online retailers either run this operation themselves or hand it to a third-party logistics provider (3PL). This guide explains how the fulfilment process works, weighs in-house fulfilment against outsourcing, and sets out the criteria that matter when choosing a 3PL partner.

What is ecommerce fulfilment?

Ecommerce fulfilment is the complete process of getting an online order to the customer. It covers five stages: receiving inventory from your suppliers, storing it in a warehouse or fulfilment centre, picking and packing each order, shipping it through one or more carriers, and processing any returns. A retailer can run fulfilment in-house or outsource it to a specialist provider, usually called a 3PL.

The term is often used interchangeably with order fulfilment, and in practice they describe the same operation. "Ecommerce fulfilment" simply stresses the online-retail context, where single-item orders, next-day expectations and high return rates set the pace.

There are three common ways to organise it:

• In-house fulfilment. You rent the space, hire the staff, buy the software and pack every order yourself.
• Third-party logistics (3PL). You send your stock to a fulfilment provider, who stores it and picks, packs and ships orders on your behalf. You keep ownership of the inventory; the 3PL runs the operation.
• Dropshipping. You never hold stock; the manufacturer ships directly to your customer. It removes the fulfilment problem but also removes your control over quality, branding and delivery times.

Fulfilment matters commercially because it sits behind the two things shoppers judge you on after checkout: how fast the order arrives and what condition it arrives in. It is also, for most online retailers, one of the largest operating costs after the product itself.

How does the ecommerce fulfilment process work?

Order fulfilment runs as a chain of five linked steps: goods-in, storage, picking and packing, delivery, and returns. An order can only move as fast as its slowest link, which is why fulfilment providers obsess over dispatch cut-off times and inventory accuracy rather than any single stage.

1. Receiving and goods-in

Stock arrives from your factory or supplier and is checked against the purchase order, inspected for damage and booked into the warehouse management system. Until goods-in is complete, the stock cannot be sold, so slow receiving quietly delays everything downstream.

2. Storage and inventory management

Each product (SKU) is put away in an assigned location: shelf, bin or pallet space, depending on its size and how fast it sells. The warehouse management system (WMS, the software that tracks what is where) keeps a live inventory count, so your store shows accurate availability and you know when to reorder. Inventory accuracy underpins everything else: overselling an item that is not on the shelf is one of the fastest ways to lose a customer.

3. Picking and packing

When an order comes in, it drops from your store into the WMS. A picker collects the items, a packer checks them, adds any inserts or branded packaging, and seals the parcel with the right label and customs documentation if it is crossing a border. The two numbers to watch here are pick accuracy (was it the right item?) and dispatch time (did it leave within the agreed cut-off?).

4. Shipping and delivery

The parcel is handed to a carrier, or to several: most fulfilment operations route orders across carriers depending on destination, weight, speed and cost. For international orders this stage includes customs treatment: deciding who pays duties and taxes, and making sure the right data accompanies the parcel. Tracking events flow back to you and your customer until delivery.

5. Returns

A percentage of orders will come back; in categories such as fashion it can be a substantial one. Returns processing means receiving the parcel, inspecting the item, deciding whether it goes back to stock, and triggering the refund or exchange. A slow returns loop costs money twice: the item sits outside sellable stock, and the customer waiting for a refund is unlikely to order again. For cross-border sellers, international returns add another layer, because the parcel has to travel back economically across a border.

In-house fulfilment vs 3PL: which model fits your business?

In-house fulfilment gives you full control and suits low volumes or products that need special handling; a 3PL turns fixed costs into variable ones and scales with your sales. The deciding question is simple: is packing orders the best use of your time and capital?

Swipe horizontally to view the full comparison table.

In-house keeps its place. If you ship a handful of orders a day, hold few SKUs, or sell something that needs hand-finishing or careful quality control, running your own fulfilment is often cheaper and better. The case for a 3PL builds as volume grows, as orders start crossing borders, and as the hours spent packing crowd out the work that grows the business. Plenty of retailers run a hybrid: core markets fulfilled in-house, international orders through a 3PL with fulfilment centres closer to those customers.

How to choose a 3PL fulfilment partner

Choose a 3PL on eight criteria: the location of its fulfilment centres relative to your customers, platform integrations, inventory visibility, carrier options, cross-border capability, returns handling, the service levels it will commit to in writing, and pricing transparency. A low price per pick can hide an expensive operation, so model the total cost before comparing rates.

Location and network. Stock should sit close to the customers who buy it. If most of your orders are domestic, fulfilment services in the UK will keep delivery times short. If you sell into Europe, the USA or Asia-Pacific in meaningful volume, a provider with fulfilment centres in those regions lets you fulfil locally, cutting delivery time and shipping cost per order. Holding stock overseas changes your import flows and tax obligations and adds inventory and compliance complexity, so treat regional fulfilment as a strategic step: decide on lane economics and return rates, and take specialist tax advice where needed.

Integrations. The 3PL's system must connect to your ecommerce platform and marketplaces so orders flow in and stock levels flow back automatically. Ask which platforms are supported natively, whether there is an API, and how quickly inventory updates reach your storefront.

Inventory visibility. You should see your stock position in real time through a dashboard or reporting feed; if checking stock means chasing the warehouse by email, the provider fails this test. Live data prevents overselling and tells you when to reorder.

Delivery options. A good 3PL offers a choice of carriers and service levels per destination, so you can balance speed against cost instead of being locked to one network.

Cross-border capability. If you sell internationally, ask how the provider handles customs and taxes. Can it ship DDP (Delivered Duty Paid, where you settle duties and taxes so the customer gets no surprise charge at the door) as well as DAP/DDU (where the customer pays on arrival)? For B2C orders into the EU, does it support IOSS, the EU's Import One-Stop Shop scheme for collecting VAT at checkout on qualifying low-value consignments? A partner that treats customs clearance as part of fulfilment, not an afterthought, saves you refused parcels and angry emails.

Returns. Ask how returned items are received, inspected and put back into sellable stock, and how international returns get back economically. Returns handled badly undo the savings made everywhere else.

Service levels and accuracy. Get the commitments in writing: dispatch cut-off times, same-day dispatch rates, pick accuracy, goods-in turnaround. Then ask how they are measured and reported to you.

Pricing transparency. A quote should itemise every fee so you can model your real cost per order and compare providers like for like (see the section on costs below).

Shortlist checklist: questions to ask a 3PL

• Where are your fulfilment centres, and which carriers do you use from each?
• Do you integrate with my platform and marketplaces out of the box?
• Can I see my inventory in real time, via dashboard and API?
• What is your order cut-off for same-day dispatch, and what dispatch and pick-accuracy rates will you commit to?
• How do you handle customs, duties and taxes on international orders, including DDP and IOSS?
• How do you process returns, and how quickly do returned items go back on sale?
• What exactly is on the invoice: goods-in, storage, pick, packaging, delivery, returns, account fees?
• What happens at peak: do you cap my volumes, and are there seasonal surcharges?
• What are the notice period and exit terms if I want to leave?

When should you switch to a 3PL?

Switch when fulfilment starts limiting the business rather than supporting it. The usual triggers: order volume outgrowing your space, missed dispatch cut-offs, peak periods you cannot staff, international orders you cannot serve competitively, or founders spending their days packing boxes instead of running the company.

More specifically, the signs tend to look like this:

• Volume. Orders are climbing, and every response (more space, more staff, more shifts) adds fixed cost you carry all year for a peak that lasts weeks.
• Errors. Wrong-item and missed-dispatch complaints are rising because the operation depends on a few overstretched people.
• Geography. A growing share of orders comes from abroad, and a domestic-only setup makes delivery slow and expensive for exactly the customers you want more of.
• Opportunity cost. The hours going into fulfilment would generate more value in buying, product or marketing.
• Seasonality. Your peak is sharp, and a shared 3PL operation absorbs it better than a warehouse sized for your quietest month.

Timing matters as much as the decision itself: plan the move for your quiet season, never mid-peak (more on this in the FAQ below).

How much does ecommerce fulfilment cost?

3PL pricing is modular: you pay separately for goods-in, storage, picking and packing, packaging materials, delivery and returns, sometimes with an account or technology fee on top. There are no meaningful standard rates: cost per order depends on product size and weight, SKU count, order profile and destinations. Compare providers by modelling your own typical month against each itemised quote.

What drives your cost up or down, in qualitative terms:

• Product size and weight. Storage is priced on space, delivery on weight and dimensions. Small, light, uniform products are cheap to fulfil; bulky or heavy ones are not.
• SKU count and order profile. Many SKUs with slow rotation cost more to store per unit sold. Multi-item orders cost more to pick than single-item ones.
• Service level. Same-day dispatch, premium packaging and faster delivery options all price above the baseline.
• Destinations. Cross-border delivery, customs handling and international returns add cost per order compared with domestic.
• Seasonality. Some providers apply peak surcharges or minimum volume commitments; ask about these while you are still comparing quotes.

Two practical warnings. First, watch the fees that do not appear in the headline rate: goods-in charges, minimum monthly billing, long-term storage surcharges for slow stock, non-standard packaging. Second, compare total monthly cost for your real order mix — the per-pick price on its own is easy to make look cheap by moving cost elsewhere on the rate card. For international orders, the biggest hidden cost is rarely on the rate card: failed deliveries, returns and the support time they generate often cost more than small per-parcel savings — a provider with a higher pick price but a better delivery success rate can be the cheaper one.

Ecommerce fulfilment with Asendia

Asendia supports ecommerce retailers with order fulfilment services that connect storage, picking and packing with cross-border delivery and returns. Retailers can talk to the sales team about their volumes, destinations and integration requirements to confirm the right operating set-up.

Frequently asked questions

Is ecommerce fulfilment the same as order fulfilment?

For practical purposes, yes. Both describe receiving, storing, picking, packing, shipping and processing returns. "Order fulfilment" is the broader logistics term and also covers B2B orders shipped to businesses; "ecommerce fulfilment" is the same chain applied to online retail orders going to consumers, where small parcels, fast dispatch and frequent returns shape the operation.

What does 3PL mean?

3PL stands for third-party logistics: a company that stores your inventory and picks, packs and ships your orders under contract, while you keep ownership of the stock and the customer relationship. A 3PL differs from dropshipping, where the supplier owns the stock, and from a freight forwarder, which moves bulk goods between businesses rather than fulfilling individual customer orders.

Can a 3PL handle international orders, customs and taxes?

The capable ones can, and it should be a core selection criterion if you sell abroad. Look for support for DDP delivery, where duties and taxes are settled upfront so your customer faces no charge at the door, alongside DAP/DDU options where the customer pays on arrival. For B2C sales into the EU, ask about IOSS, the scheme that lets you collect EU VAT at checkout on qualifying low-value consignments (currently up to €150) — implemented correctly across checkout, invoicing and customs data, the recipient faces no VAT collection or handling charges on delivery. Note that since July 2026 the EU applies a temporary €3 customs duty per item type to low-value consignments regardless of IOSS (in place until July 2028) — ask your 3PL how it is handled.

How long does it take to move fulfilment to a 3PL?

There is no fixed timescale; it depends on how many SKUs you hold, how complex your integrations are and how much stock has to move. The migration normally runs in stages: connecting your store to the provider's system, transferring and booking in stock, running test orders, then switching order flow across. The advice from retailers who have done it: never migrate during peak season, and keep a buffer of stock available while the new operation beds in.

Ecommerce fulfilment is everything that happens between a customer clicking "buy" and the parcel arriving at their door: receiving stock, storing it, picking and packing orders, shipping them and handling returns. Online retailers either run this operation themselves or hand it to a third-party logistics provider (3PL). This guide explains how the fulfilment process works, weighs in-house fulfilment against outsourcing, and sets out the criteria that matter when choosing a 3PL partner.