Prioritize WMS capability and API/EDI connectivity, proximity to highways and ports, available racked and temperature-controlled space, cross-dock throughput, pick accuracy rates, and documented SLA performance. Evaluate labor skill availability and peak-season staffing plans to ensure consistent order-cycle times and service levels.

Carrier access determines lane density and pricing: proximity to major routes and port links enables zone-skipping and consolidated shipments, lowering average shipping spend and transit time variability. Select 3PLs with established carrier contracts and regional lane expertise to optimize routing and reduce delivery exceptions.

Require a modern WMS with real-time inventory, API endpoints or EDI for order and ASN exchange, configurable order routing rules, and reporting dashboards. Look for support for barcode/RFID scanning, batch tracking, and automated alerts to reduce exceptions and improve pick/pack accuracy.

Negotiate transparent storage (by pallet/SKU), pick-and-pack, inbound handling, and minimums. Include volume-tiered pricing, clear peak-season adjustments, SLA credits for performance shortfalls, and defined onboarding/ramp timelines to control total cost-per-order as demand changes.

Assess multi-site capacity options, contingency labor plans, backup carriers, and surge staffing agreements. Review the 3PL’s disaster recovery procedures, historical performance during peaks, flexibility in labor/space allocation, and the ability to provide short-term increases in throughput without compromising SLAs.