Prioritize carrier and cross‑border connectivity, customs handling experience, WMS/API integration, dock and racking capacity, SLA clarity for lead times and accuracy, and scalability for seasonality. Also verify insurance, security protocols, and local labor skillsets to ensure consistent fulfillment performance.

Closer proximity can reduce inland transit distance and fuel costs, shorten lead times to neighboring markets, and lower cross‑dock handling. However, border procedures and broker efficiency materially affect predictability; factor in customs timelines and carrier reliability when modeling landed cost and service windows.

Confirm pick‑and‑pack throughput, returns processing, kitting, SKU storage density, order accuracy metrics, same‑day/next‑day options, and the 3PL's ability to integrate with your storefronts and ERPs. Review historical performance for peak periods and request references for similar SKU velocity profiles.

Negotiate clear SLAs with measurable KPIs, pricing transparency for storage and accessorials, minimum notice for capacity changes, liability and insurance limits, and exit terms for stock repatriation. Ensure contract includes audit access, regular reporting cadence, and remediation steps for SLA non‑performance.