TSO

TSO is the outbound counterpart to TSI.
 It describes any stock that leaves an Amazon facility not because it was sold to a customer, but because Amazon is moving it within its network for strategic or operational reasons.

This internal movement supports Amazon’s large scale logistics operations and ensures that products are placed in the best possible locations to meet customer demand.

Common scenarios where TSO occurs:

• Inter FC transfers: Inventory is sent from one fulfilment centre to another to balance stock levels
• Cross dock routing: Products are shipped out of an IXD to downstream FCs
• Demand rebalancing: Amazon shifts items based on regional demand spikes
• Space optimisation: Low priority products are moved out of FCs with high utilisation
• Carrier or routing consolidation: Inventory is forwarded to hubs for more efficient shipping

TSO shipments do not involve customer orders.
 They are entirely operational transfers within Amazon’s supply chain.

Why Amazon uses TSO:

• Improve instock rates across regions
• Enable faster delivery speeds (1 day or same day)
• Reduce fulfilment costs by placing stock closer to customers
• Avoid overstocking certain FCs and understocking others
• Maintain efficiency across the entire network

Benefits for Amazon:

• Optimised inventory distribution
• Smoother FC throughput
• More accurate regional forecasting
• Lower shipping costs for last mile delivery

Benefits for vendors and sellers:

• Higher Buy Box availability
• Better customer experience due to faster delivery
• Reduced cancellation or long ship time risk
• Stronger sales velocity in high demand regions

Example:
A fulfilment centre in Phoenix ships 5 pallets of popular toys to a fulfilment centre in Miami due to growing regional demand.
This movement is recorded as TSO (Trans Shipment Out) for Phoenix and TSI for Miami.

Why It Matters:
TSO is essential for understanding how Amazon dynamically manages inventory across its massive network.
It ensures that products are always placed where they are needed most, improving both operational efficiency and customer satisfaction.

In short:
TSO (Trans Shipment Out) refers to inventory sent out from an Amazon facility to another location within the network as part of internal redistribution and optimisation.