Prioritize real-time WMS/API integration, published SLAs for pick/pack/ship, bonded and temperature-controlled storage, returns and kitting processes, multi-carrier connectivity, and demonstrated peak-season labor scalability to maintain service levels and predictable cost-to-serve.

Proximity to ports, major highways and air freight lanes reduces transit miles and inland drayage, lowering landed costs and lead times. Carrier density enables competitive freight rates and flexible routing; assess last-mile partners, cross-dock options, and typical transit SLA windows to model true distribution costs.

Verify bonded status and customs brokerage capabilities, import/export documentation workflows, security and inspection protocols, trade compliance support, and EDI/API connectivity for filings. Confirm the 3PL's experience handling tariffs, duties deferment, and local regulatory inspections to avoid clearance delays.

Require detailed cost-to-serve models that break down storage, handling, pick/pack, and outbound freight by SKU or customer channel. Inspect historical SLA reports, chargeback policies, inventory accuracy metrics, and options for pilot or ramp trials to validate performance under real operating conditions.