Evaluate WMS capabilities (API integrations, real-time inventory), SLA commitments for order accuracy and lead times, material handling equipment, racking and storage density, and the 3PL’s ability to scale labor and shifts. Request site tours, technology demos, and sample KPI reports to validate operational fit.

Key factors include proximity to major road corridors, carrier density and frequency, customs clearance times, and access to cross-dock or consolidation services. Optimize lane assignments and choose 3PLs with multiple carrier contracts to reduce parcel spend and mitigate single-carrier disruptions.

Prioritize accurate pick-and-pack operations, returns processing, kitting and light assembly, same/next-day fulfillment options, and transparent inventory visibility. Ensure the 3PL can support SKU proliferation and seasonal volume spikes with flexible labor and clear escalation paths.

Compare total cost of ownership including storage density, pick/pack rates, inbound receiving fees, and chargebacks for errors. Evaluate SLA language for accuracy, on-time shipment, and penalties, and request historical performance data to quantify service variability and mitigation measures.