There's no universally right fulfilment model — the best choice depends on your channel mix, order volume, product type and how much operational control you want to retain. Here's how the three main options actually compare.
Fulfilment by Amazon (FBA): strengths and constraints
FBA gives your Amazon listings Prime eligibility and access to Amazon's fulfilment and returns infrastructure, which for many UK sellers materially improves conversion and search visibility on the Amazon marketplace itself. The trade-off is real control cost: Amazon's storage fees (particularly punitive for long-term storage of slow-moving stock), strict prep and labelling requirements, and limited flexibility for custom packaging or brand experience compared to a self-managed alternative.
FBA works best for sellers whose business is genuinely Amazon-centric — if a large share of your revenue already comes through the marketplace, the Prime badge and fulfilment convenience typically outweigh the fee structure and control trade-offs.
Running your own warehouse
Owning your fulfilment gives full control over packaging, branding, quality control and the customer experience at every touchpoint, and at sufficient volume the per-order cost can undercut both FBA and 3PL alternatives since you're not paying another party's margin on top of the underlying cost. The trade-off is significant upfront investment (lease, racking, equipment, staffing) and the operational burden of managing warehouse staff, systems and peak-season capacity yourself — a genuine full-time undertaking, not a side activity.
Third-party logistics (3PL)
A 3PL sits in between — professional fulfilment infrastructure and expertise without the capital investment or day-to-day management burden of your own facility, typically on a variable cost structure that scales with your order volume rather than requiring fixed upfront investment. Multi-channel retailers particularly benefit from a good 3PL, since most support Shopify, your own website, Amazon, eBay and other marketplaces from a single stock pool, whereas FBA inherently ties inventory to the Amazon ecosystem (Amazon does support multi-channel fulfilment from FBA stock, but with its own fee structure and limitations).
Comparing the three head to head
- Speed to launch: FBA and 3PL are both faster to start than building your own warehouse from scratch.
- Cost at low volume: 3PL and FBA avoid fixed infrastructure cost; owned warehousing only becomes cost-competitive at meaningful volume.
- Cost at high volume: owned warehousing typically wins on per-order cost once volume justifies the fixed investment.
- Brand experience control: owned warehouse offers the most control, 3PL a good middle ground (many support custom packaging), FBA the least.
- Multi-channel flexibility: 3PL is generally the most channel-agnostic; FBA is optimised for, and somewhat tied to, Amazon.
Hybrid strategies many UK retailers actually use
A common and often sensible approach is running a hybrid model — using FBA specifically for Amazon orders to capture the Prime badge and marketplace visibility benefits, while fulfilling your own website and other marketplace orders through a 3PL or owned warehouse for better margin and brand control. This isn't operationally trivial (it means managing split inventory pools and more complex stock allocation logic) but for retailers with a meaningful multi-channel presence, it often captures the best of each model's strengths.
Making the decision for your business
Map your actual channel mix, current and projected order volume, product type (fragile, bulky, high-value, or requiring special handling all shift the calculation), and how much you personally value direct control over the customer experience versus operational simplicity. Revisit the decision periodically rather than treating it as permanent — many successful UK retailers move from FBA-only, to a 3PL, to eventually an owned or hybrid warehouse model as volume and channel complexity grow.
Understanding the true all-in cost of each option
A fair comparison needs the full cost stack for each option, not just the headline fee — FBA's storage and fulfilment fees, a 3PL's receiving, storage, pick-and-pack and outbound charges, and an owned warehouse's rent, rates, utilities, equipment and staffing costs all need modelling against your actual order profile (average items per order, product weight and dimensions, return rate) rather than a generic estimate. It's common for a retailer to underestimate FBA's long-term storage fees on slower-moving stock, or a 3PL's minimum volume commitments, only discovering the true cost once several months of invoices have accumulated.
Piloting before committing fully
Where feasible, trial a new fulfilment model on a subset of your product range or order volume before migrating entirely — moving your slower-moving SKUs to FBA first, or trialling a 3PL with a portion of orders while keeping your existing process running in parallel, lets you validate service quality and true cost before fully committing. This staged approach reduces the risk of a disruptive, all-or-nothing transition that affects your entire order volume if the chosen model underperforms in practice.
How This Connects to the Rest of Your Operation
Getting fulfilment by amazon vs. your own warehouse vs. 3PL: a UK comparison right is rarely a one-off task — it tends to need revisiting as the rest of the business changes around it. We cover this in more detail in Fulfilment by Amazon vs Fulfilment by Merchant: A UK Seller's Comparison, which is worth reading alongside this piece.
For related reading: We cover this in more detail in Marketplace Channel Management Software: Keeping Amazon, eBay and Your Own Store in Sync, which is worth reading alongside this piece. We cover this in more detail in Negotiating 3PL Contracts and Service Level Agreements That Protect You, which is worth reading alongside this piece.