Prioritize proximity to major transport routes and carriers, throughput capacity, slotting and racking flexibility, SLA history, staffing stability, and the 3PL’s experience with your channel mix (eCommerce vs B2B). Confirm inbound cutoffs, outbound transit times, and contingency capacity for peaks.

Location near highways, rail, ports and last-mile carriers shortens lane miles and reduces fuel and carrier surcharges. Dense carrier networks enable competitive freight rates and more reliable service windows, lowering average transit times and improving on-time delivery for multiple channels.

Compare storage (per pallet/cubic), receiving and put-away fees, pick-and-pack rates, kitting/assembly charges, outbound cartonization and labeling, minimums, billing cadence, and pass-through carrier costs. Include peak surcharges, chargeback policies, and onboarding/setup fees in TCO modeling.

Look for APIs or EDI for order flow, WMS visibility for inventory and order status, OMS compatibility, returns management workflows, and standardized KPI/reporting (OTD, inventory accuracy, pick/pack cycles). Confirm access to real-time dashboards and regular exception notifications.

Assess historical peak performance, surge staffing plans, flexible storage options, dedicated vs shared capacity models, and documented returns workflows. Request references for seasonal clients, review SLAs under peak load, and verify contingency plans for labor or carrier shortfalls.