Prioritize carrier network depth, demonstrated handling for your product class, WMS/API readiness, security and bonded-capacity, and measurable SLAs (order cycle time, picking accuracy). Also evaluate proximity to airports/border crossings, seasonal road reliability, and the 3PL's contingency routing and inventory replenishment capabilities.

Use a total-cost model that includes transit time variability, fuel and surcharge assumptions, handling fees, duties, and inventory carrying cost. Request historical transit-time distributions, per-SKU pick-pack metrics, and examples of cost-to-serve by channel (eCommerce vs B2B) to align commercial terms with expected volumes.

Critical services include bonded storage, secure high-value handling, cross-dock and short-term staging, and scalable racking. Technology must include a modern WMS with API carrier connectivity, real-time inventory visibility, exception reporting, and SLA dashboards to drive predictable omnichannel performance.

Require documented security protocols, insurance and loss-prevention statistics, contingency routing plans for road or weather disruption, backup pick-pack capacity, and incident-response SLAs. Include audit rights and periodic drills to ensure the 3PL can maintain service under regional constraints.