Prioritize real-time WMS integration and inventory visibility, consistent SLA and throughput guarantees, strategic location relative to customers and ports/airports, demonstrated carrier connectivity, and documented returns/omnichannel workflows. Also assess surge staffing plans and local labor availability for peak periods.

Proximity to ports, airport corridors and quality road links shortens transit and enables zone-skipping and consolidation strategies that reduce landed cost. Choose a 3PL with negotiated LTL/FCL contracts and regular consolidation schedules to improve transit predictability and lower per-unit freight spend.

Require flexible floor space and racking, segregated returns processing bays, temperature-controlled areas when needed, and a WMS with API/EDI connectivity for order routing. Verify the 3PL’s surge staffing plan, documented reverse-logistics process, and ability to scale temporary labor and equipment during peaks.

Model fixed versus variable fees, pick/pack and storage rates, inbound/outbound freight, inventory carrying costs, and SLA penalties. Request sample invoices, run a cost-per-order scenario using your SKU mix and volumes, validate key performance metrics, and conduct a short pilot to confirm assumptions before committing.