Prioritize transit times to key customer clusters, dock and staging capacity, inbound cutoffs for major carriers, pick-and-pack productivity metrics (PPH), and visibility through WMS/WCS integrations. Also evaluate scalability for peak seasons and documented SLAs for accuracy and on-time dispatch.

Common models include storage-per-pallet, transactional pick-and-pack fees, and throughput-based billing. Negotiate clear handling rules (carton vs. piece), peak season rates, free days for storage, chargeback triggers, and minimums. Ask for sample cost modeling using your SKU velocity and order profile.

Look for certified storage for regulated goods, temperature-controlled zones, bonded or customs facilitation if cross-border trade occurs, documented chain-of-custody, and robust safety and audit protocols. Ensure the 3PL maintains insurance and regulatory registrations applicable to your product class.

Require real-time WMS APIs for inventory, ASN support, EDI or API order flows, event-based tracking for shipments, and partner portals for reporting. Confirm latency, data schemas, and a documented onboarding plan for SKU mapping, lot/serial tracking, and returns processing.