What Is a 3PL vs 4PL? The 3PL Subcategories Every Ecommerce Seller Should Know

3PL vs 4PL

A 3PL runs your physical fulfillment operations, including receiving, storage, picking, packing, shipping, integrations, and returns. A 4PL manages the wider supply chain by coordinating multiple 3PLs, carriers, freight forwarders, customs brokers, and technology providers. This guide explains the practical differences between the two models and examines the 3PL categories ecommerce sellers need to understand, including DTC, wholesale, multichannel, FBA preparation, apparel, returns, freight, and asset based operations. It also shows why many mid market sellers benefit from a specialized, directly accountable 3PL.