Switching 3PL is expensive and disruptive, so it pays to get the choice right the first time. Here's what actually matters when you're comparing UK fulfilment partners — beyond the price per order on the quote.
Licensing for what you actually sell
Not every 3PL can legally handle every product type. Alcohol requires FHDS (Fulfilment House Due Diligence Scheme) approval from HMRC — if a warehouse doesn't hold it, they legally cannot store and despatch alcohol orders on your behalf. Other categories (health products, certain cosmetics) carry their own handling considerations. Ask directly what licences and accreditations a 3PL holds for your specific product category before anything else.
Minimum order volumes and contract length
Many larger 3PLs set a minimum order volume before they'll take you on, which rules out newer or smaller brands entirely. Others tie you into a long-term contract before you've had a chance to see how the relationship actually works day to day. Look for a partner that will start with your current volume — whatever that is — and let the relationship grow from there rather than gatekeeping on size.
What to ask: "What's your minimum order volume, and what's the shortest contract term you offer?" A confident 3PL will have a straight answer to both.
Does it plug into every channel you sell on
If you sell on Shopify and TikTok Shop and Amazon, your fulfilment partner needs one system that connects to all three — not three separate processes. Order management platforms like DespatchLab connect 40+ platforms (Shopify, WooCommerce, Magento, Amazon, eBay, Etsy, TikTok Shop and more) into a single stock pool, so every channel is fulfilled from the same inventory with one invoice, rather than juggling separate stock allocations per channel.
One carrier, or many?
A 3PL locked into a single courier has no fallback when that network is delayed, at capacity, or restricts a service — which tends to happen exactly when order volumes are highest. A multi-carrier setup, where the system automatically selects the best courier for each order, gives you resilience that a single-carrier operation simply can't offer. We go into this in more detail in why multi-carrier capacity matters most heading into peak season.
Where they're based — and how far that reach actually goes
Location affects real delivery performance, not just the map on their website. A depot in the Midlands "Golden Triangle" (the Northampton–Rugby–Daventry corridor) sits within same-day or next-day reach of the vast majority of the UK population, without the congestion costs of operating out of London. Ask specifically what percentage of UK postcodes they can reach next-day — a real number, not a general claim.
How they handle a sudden spike in orders
One viral TikTok video, a Black Friday campaign, or simply a strong December can generate hundreds of extra orders in days. Ask how a prospective 3PL has handled spikes in the past, and specifically what happens during Q4 — this is exactly the period covered in our Q4 and Christmas peak readiness checklist.
Who handles your returns
Returns are part of the job, not an afterthought. Ask whether returns are received, inspected, restocked and reported back into your stock system automatically, or whether that's manual work that falls back on you.
The quick checklist
- Do they hold the right licence/accreditation for your product category?
- Is there a minimum order volume or a long-term contract?
- Does their system connect to every sales channel you use?
- Do they use more than one courier, selected automatically per order?
- What percentage of the UK can they reach next-day?
- How do they handle a sudden spike in order volume?
- How are returns received, inspected and restocked?