Prioritize transit time to core markets, WMS/API integration for inventory visibility, SLAs for order accuracy and same-day/next-day options, scalability for peak volumes, and transparent billing (storage, pick/pack, returns). Also verify carrier partnerships and customs/clearance capabilities for cross-border flows.

Location directly affects linehaul and last-mile costs: warehouses closer to major highways, consolidation hubs, or port/airport nodes reduce transit miles and enable zone-skipping. For B2B, proximity to industrial clusters shortens lead times; for omnichannel retail, closer last-mile nodes improve delivery windows and reduce surcharges.

Require a cloud-based WMS with real-time inventory sync, API/EDI connectivity for OMS and carriers, event-level tracking, return management, and support for batch/lot traceability. Confirm functionality for slotting optimization, kitting, and multi-channel order routing to reduce fulfilment latency and errors.

Negotiate transparent rate cards for storage, pick/pack, receiving, and dimensionalized shipping; minimums and SLA credits for service failures; volume discounts, labor surge pricing caps for peak seasons, and clear pass-throughs for carrier fuel and accessorial charges to avoid unexpected cost drift.

Evaluate dedicated returns processing space, inspection and disposition workflows, IT support for RMA integration, turnaround times for refunds/restocks, and the 3PL's policies on refurbishment or liquidation. Request KPIs for returns throughput, resolution time, and disposition accuracy.