Article Summary:
- Providers look similar on their websites and differ a great deal once you are inside a contract
- Pricing structure matters more than headline rate, since the extras are where costs land
- Ask for service levels in writing with a remedy attached, not as a description of a good month
- Integration capability is worth testing before contract rather than at go-live
- UK-based fulfilment changes delivery times, shipping costs and returns handling for UK customers
Most fulfilment providers describe themselves in roughly the same terms. Accurate picking, fast dispatch, scalable operations, a platform that gives you visibility. Read four websites and you will struggle to tell them apart.
The differences show up later: in the invoice that does not match the quote, in the peak season where dispatch slipped, in the integration that needed three weeks of work nobody mentioned. Those things are knowable in advance, but only if you ask the right questions before signing.
This guide covers what to compare, what to ask, and what tends to go wrong.
Start With What You Actually Need
Comparing providers before you have defined your requirements means comparing them against each other rather than against your business.
Write down the following first:
- Order volume: Current and projected twelve months out. Providers price differently at different volumes, and a rate that suits you now may not suit you at double your order amount.
- SKU count and product characteristics: Size, weight, fragility, batch or expiry tracking, anything that needs special handling.
- Sales channels: Every platform and marketplace you sell through, including any you plan to add.
- Order profile: Single-item orders behave differently from multi-item baskets, and subscription boxes are different again.
- Service expectations: Cut-off times, dispatch speed, and what your customers have been promised at checkout.
- Where your customers are: Concentrated in the UK, spread across the EU, or a mix.
That last one shapes more of the decision than people expect, and it is worth taking seriously before you look at any provider.
Why Location Matters More Than It Looks
Holding stock close to your customers changes what you can offer them.
For a brand selling mainly to UK customers, UK-based fulfilment means domestic carrier rates rather than international shipping, next-day options across most of the country, and no customs step between the warehouse and the doorstep. Returns come back to a UK address rather than crossing a border, which is faster for the customer and cheaper for you.
Fulfilling the same orders from outside the UK adds duty, VAT processing and brokerage to every parcel, along with longer delivery windows and the risk of customers meeting unexpected charges on delivery.
The reverse applies if a meaningful share of your customers are in the EU. Shipping order by order from the UK into the EU carries the same per-parcel friction. Holding stock inside the single market removes it. Providers with both UK and EU sites let you split stock rather than choosing one and accepting the cost on the other.
Ask any provider where their sites are, which one your stock would sit in, and what happens if you later want to hold stock in two places.
Pricing You Can Model
Headline rates are the least useful number in a 3PL quote. Ask for the structure instead.
Get these broken out separately:
- Per-order fulfilment cost, and whether it changes by item count.
- Storage, and how it is measured. Pallet, shelf, bin or square footage all behave differently as you grow.
- Shipping, and whether you are billed the carrier rate or a marked-up one.
- Goods-in and receiving charges.
- Returns processing, per item.
- Any value-added work such as kitting or personalisation.
Then ask specifically about the extras:
- Peak season surcharges, and when they apply.
- Long-term storage fees for slow-moving lines.
- Minimum monthly spend, and what happens in a quiet month.
- Setup and integration fees.
- Notice period and exit costs.
A provider willing to model your costs at current volume and at double it is giving you something you can plan against. One who quotes a per-order rate and stays vague on the rest is not. Our breakdown of 3PL pricing in the UK explains how the line items usually fit together.
Service Levels, In Writing
Every provider will tell you their picking is accurate and their dispatch is fast. Ask for numbers, then ask what happens when they miss.
The questions worth asking:
- What is your same-day dispatch rate, and what is the cut-off time?
- What is your pick accuracy, and how is it measured?
- What were those figures last November and December, not on an average month?
- What is the remedy if you miss it?
That last one separates a service level from a description. A commitment with a credit attached behaves differently from a number on a slide. Get it into the contract.
Peak is the real test. Most operational failures happen in Q4, when volumes triple and temporary staff outnumber permanent ones. A provider confident in their peak performance will give you the figures without being pushed.
Integrations That Actually Connect
This is where onboarding most often runs over.
Ask which of your specific platforms the provider already runs, not which ones they could support. There is a meaningful gap between an existing integration and one that has been built before for someone else.
Worth checking:
- Direct connections to your channels rather than CSV imports.
- Whether stock syncs in real time or in end-of-day batches.
- How multi-channel stock is handled, and whether you get a single view.
- API access if you run anything custom.
- What data comes back to you, and in what format.
Batch syncing rather than real-time is the most common cause of overselling for multi-channel brands. It is also the sort of thing that does not come up unless you ask.
Build testing time into onboarding so gaps surface before go-live rather than during it.
Support and the People Running It
Fulfilment is a people business more than the technology suggests.
Ask who your contact will be, whether that is a named person or a shared inbox, and what happens when something goes wrong at four o’clock on a Friday. Ask about staff retention while you are at it. High turnover in a warehouse shows up as inconsistent picking and as repeated explanations of things you already explained.
Ask for client references you can speak to directly, ideally brands of a similar size to yours. A provider comfortable connecting you with an existing client is telling you something. So is one who avoids it.
Values You Can Verify
If sustainability is part of how you talk to your customers, your fulfilment partner becomes part of that claim.
Ask what is independently checked rather than self-declared. Certification such as B Corp involves external verification, where terms like eco-friendly and carbon-conscious do not. Ask about packaging materials, what happens to waste at the warehouse, and what they can report back to you on, since claims your customers might question are worth being able to evidence.
Where Things Tend to Go Wrong
Three problems come up repeatedly, and all three are avoidable at the selection stage.
Costs That Arrive Later
The quote covers fulfilment and storage. The invoice includes receiving fees, a peak surcharge and a minimum spend adjustment. Ask for a full fee schedule rather than a summary.
Losing Sight of Your Stock
Handing over fulfilment means giving up direct control of how products are stored and packed. The answer is data rather than proximity: live stock levels, order status and returns detail available whenever you need them, rather than waiting on someone else’s reporting cycle.
Communication Drifting
Shared inboxes and ticket queues turn small problems into slow ones. A named contact and a regular check-in rhythm prevents most of it.
A Shortlist Checklist
Once you have two or three providers in front of you, run each through the same questions.
| Area | What to Confirm |
|---|---|
| Locations | Which site holds your stock, and can it be split? |
| Pricing | Full fee schedule, modelled at current and double volume. |
| Service levels | Dispatch rate, pick accuracy, last peak, remedy for misses. |
| Integrations | Your specific platforms, real-time or batch, testing time. |
| Support | Named contact, escalation path, staff retention. |
| References | Two clients of similar size you can speak to. |
| Exit | Notice period, exit fees, stock transfer process. |
Score them against the same criteria rather than against each other’s sales material.
Before You Commit
Visit the warehouse if you can. Fifteen minutes on a warehouse floor tells you more about how a provider operates than any amount of documentation. Look at how stock is organised, how busy the packing benches are, and whether anyone seems to know where things are.
Read the exit clause as carefully as the pricing. Switching providers is disruptive at the best of times, and a long notice period or a punitive exit fee turns a fixable problem into a stuck one. Our guide on switching 3PL providers covers what that process involves.
If you are still weighing outsourcing against keeping fulfilment in-house, our comparison of 3PL and in-house fulfilment works through the trade-offs. And if you want to see how one provider answers the questions above, our UK 3PL services page sets out how we work.
Frequently Asked Questions
What Should I Ask a 3PL Before Signing?
Full fee schedule including peak surcharges and minimums, same-day dispatch rate and pick accuracy with a remedy attached, which of your specific sales channels they already integrate with, who your named contact will be, and two client references of similar size.
How Long Does It Take to Onboard With a 3PL?
It varies with how many channels need connecting and how much product data needs setting up. Integration and testing usually run alongside your first stock delivery rather than before it, so system setup and goods-in happen in parallel.
Should I Choose a UK 3PL or Fulfil From Overseas?
It depends where your customers are. UK-based fulfilment gives domestic carrier rates, next-day options and no customs step for UK orders. If a large share of your customers are in the EU, holding stock inside the single market avoids the same friction in reverse.
How Do I Compare 3PL Quotes Fairly?
Ask every provider for the same fee schedule broken into the same line items, then model each at your current volume and at double it. Comparing per-order rates alone misses storage, receiving and peak charges, which is usually where the difference sits.
What Size Business Needs a 3PL?
Around 500 orders a month is where the economics tend to shift, though SKU count, multi-channel selling and peak season pressure often trigger the move before volume does.
