Require clear KPIs and reporting: on-time order fulfillment, order accuracy, inventory accuracy, dock-to-stock cycle time, and chargeback thresholds. Include SLA remedies, capacity scaling clauses, and periodic operational reviews to ensure alignment with peak season demand and new SKU introductions.

Map carrier lanes, terminal locations, and average transit times; request sample rate audits and proof of regular pickup schedules. Consider multimodal connectors and proximity to regional hubs. If helpful, ask prospective 3PLs for historical modal split and linehaul performance data.

Look for WMS API support for real-time inventory, EDI or API order transmission, ASN capability, batch/LPN tracking, and return management. Confirm reconciliation processes and cycle-count cadence to maintain inventory visibility across channels.

Evaluate fixed storage, handling rates, labor productivity, inbound consolidation, and outbound linehaul. Consider inventory velocity, safety stock needs, and service-zone coverage. Use a landed-cost model that includes transport, handling, and working capital to compare scenarios.