Prioritize SLA metrics (order accuracy, cut-off times, transit performance), WMS integration and API reliability, slotting and pick-path efficiency, returns handling throughput, and transparent billing. Consider scalability of labor and capacity during peak seasons and the 3PL’s carrier portfolio for your key lanes.

Map cost-to-serve per SKU including storage, handling, and outbound freight. Compare carrier-negotiated rates, zone optimization, and consolidation capabilities. Negotiate bundled services (pick-and-pack, cross-dock) and monthly minimums to align pricing with volume variability.

Require a WMS with real-time inventory, RMA and returns workflow, EDI/API integrations for OMS and marketplaces, barcode/scan-based receiving and picking, and reporting dashboards. Confirm uptime SLAs and data security standards to protect order integrity.

Evaluate proximity to major highways and border crossings, density of parcel and LTL carrier networks, and typical transit times to your customer clusters. Check for local cross-dock options, scheduled carrier cutoffs, and last-mile partners that support delivery SLAs for retail and D2C orders.