Prioritize WMS functionality and integration with your storefront, EDI/API connectivity, inventory visibility, and real-time reporting. Assess throughput, pick accuracy, slotting strategy, and how the 3PL handles peak surges and onboarding timelines. Request KPIs and reference site visits to validate execution.

Consider proximity to interstates, rail terminals, and the port for modal flexibility; evaluate carrier hubs and parcel zone boundaries to reduce transit days and shipping zones. Factor in regional demand density to balance inventory placement versus transportation cost.

Common models include ambient and cold storage, pick-and-pack, kitting and light assembly, B2B pallet distribution, and returns processing. Look for 3PLs offering multi-channel routing logic and same-day or next-day local fulfillment capabilities when omnichannel speed is required.

Request a detailed rate card covering storage, receiving, pick/pack, returns, and value-added services. Clarify handling rules, dimensional weight practices, chargebacks for inventory inaccuracies, minimums, and SLA penalties. Model total cost-per-order across expected SKU mixes and volumes.