Prioritize SLA and KPI definitions (order accuracy, on-time shipping), WMS/API connectivity, inventory visibility, availability of temperature-controlled zones, turnaround times for returns, and the provider's experience with peak-season labor plans and value-added services like kitting and labeling.

Location affects road transit time to major markets, access to regional carriers, and cost of first/last-mile delivery. A site with direct access to main distribution corridors reduces fuel and transit fees, enables more consolidation options, and can lower landed costs through shorter transit lanes and fewer handoffs.

Ask for real-time WMS connectivity (APIs/EDI), automated inventory updates, SKU-level traceability, batch/lot and temperature controls if needed, omnichannel order routing, integrated returns processing, and reporting dashboards for cost and performance monitoring.

Expect a regional labor pool with seasonal fluctuations; verify the 3PL's contingency plans for peak windows, temp labor partnerships, and overtime policies. Also confirm flexible space options or contract clauses for rapid capacity increases and transparent pricing for surge volumes.