Prioritize measurable capabilities: mature WMS with API/EDI, proven SLA and KPI reporting, scalable storage and labor, value-added services (kitting/returns), and clear carrier integrations. Also evaluate proximity to highways, cross-dock capacity, customs processing experience, and contract flexibility for seasonal peaks.

Carrier density and proximity to major arterial routes reduce pickup windows and lower transit times, which directly cuts shipping costs and inventory days. Efficient cross-border processing near the facility reduces delays and duties handling, improving predictability for international eCommerce and B2B deliveries.

Require a modern WMS with real-time inventory, API/EDI connectivity, advanced picking (batch/zone/wave), returns management, and transaction-level reporting. SLA terms should cover order accuracy, on-time shipping, and clear penalties or remediation for missed KPIs to protect omnichannel customer experience.

3PLs typically offer a mix of fixed-monthly storage, per-pick and per-shipment fees, and value-added service charges. Negotiate volume tiers, seasonal rate caps, short-term labor pass-throughs, and performance-based incentives. Insist on transparent cost components and carve-outs for peak surcharges to maintain budget visibility.