Prioritize geographic access (port/airport proximity), bonded customs capabilities, WMS/API integration, pick-and-pack throughput rates, SLA metrics for order cycle times, labor scalability for peaks, and transparent cost-to-serve reporting that separates storage, handling, and transportation line items.

Expect a combination of base storage fees, per-pick and per-order handling charges, inbound/outbound pallet handling, and value-added service fees. Forecast using seasonally adjusted pick rates and cube utilization; negotiate volume tiers, minimums, and included labor hours to control variability.

Confirm bonded storage licenses, experience with IOSS/VAT processes, EORI handling, electronic customs filing, and established procedures for duty deferment. These capabilities reduce release times at ports and ensure compliance for both EU and UK-bound shipments.

Assess the 3PL’s carrier contracts, diversity of parcel and pallet partners, regional SLA history, and real-time tracking integration. Validate average transit times to key postal codes, contingency plans for carrier failures, and the 3PL’s ability to support next-day or same-day delivery windows.

Require API-enabled WMS with real-time inventory visibility, EDI or API order flows, returns management, batch/lot tracking for traceability, and reporting dashboards for fill rates, OTIF, and inventory aging. Confirm test environments and documented integration timelines.