Require clear KPIs and reporting: on-time-in-full (OTIF), order cycle time, inventory accuracy, dock-to-stock lead time, returns processing time, and monthly throughput trends. Where helpful, ask for historical SLA attainment and penalties tied to those KPIs to validate ongoing performance.

Location affects carrier access, last-mile rates, and transit windows. A site in Gwynedd can lower real-estate and labor costs while offering direct road links to northern UK hubs and coastal gateways, which may reduce certain lane costs but requires analysis of carrier density and onward routing to major urban centers.

Prioritize configurable racking, multi-door dock capacity, IT integration (WMS + marketplace APIs), returns processing, and options for temperature control or value-added services. Also verify peak-season scalability, labor shift patterns, and security/compliance controls for higher-value SKUs.

Compare unit economics: storage per pallet or per cubic metre, picking and packing fees, throughput tiers, add-on charges (labour, packaging, returns), and minimums. Also review contract flexibility for seasonal volume swings and the impact of service-level credits on total landed cost.