Prioritize proximity to the Port of Belfast and major motorways for inbound/outbound efficiency, carrier density for last-mile options, available labor pools, flexibility in lease and capacity, warehouse tech (WMS, EDI/API), and demonstrated experience with eCommerce returns, kitting, and value-added services.

Cross-border operations require 3PLs with customs-clearing experience, bonded storage if needed, and proven processes for commodity codes and declarations. Your inventory strategy should account for lead times, buffer stock for customs delays, and the 3PL’s ability to manage paperwork and duty deferral where applicable.

Look for a modern WMS with API/EDI connectivity, real-time inventory visibility, order management, returns workflow, and reporting. Confirm the partner’s integration experience with major eCommerce platforms, carrier rate-shopping, and automated shipping label generation to maintain SLA compliance and reduce manual exceptions.

Key cost drivers include rent per pallet or sqm, pick-and-pack labor rates, handling fees for returns and value-added services, inbound/outbound transportation costs, minimums and slotting charges, inventory storage duration pricing, and any technology or onboarding fees that affect total landed cost.

Negotiate pilot agreements with limited SKUs and clear KPIs (pick accuracy, lead time, OTIF). Insist on transparent reporting, defined onboarding milestones, and flexible minimums. Validate integrations, run peak simulations, and require contingency plans for capacity spikes and supply interruptions.