Cargo that is well packed and properly palletized moves faster and arrives in better condition — pallets are handled by forklift at every transfer point along an international route, and non-palletized or poorly stacked cargo slows that handling down and increases the risk of damage.
Standard pallet sizes matter for container utilization. A 20ft or 40ft container has fixed internal dimensions, and pallets sized to standard dimensions (roughly 1.0m x 1.2m or 1.1m x 1.1m, depending on region) tessellate efficiently; irregular pallet sizes waste container space and can increase your effective freight cost.
Weight distribution across a pallet affects both handling safety and, for air freight specifically, how chargeable weight is calculated. Cargo stacked unevenly is more prone to shifting in transit, which is one of the more common causes of in-transit damage claims.
For cargo with any fragility, temperature sensitivity, or unusual shape, it is worth discussing packing requirements before goods are palletized rather than after — some packing decisions are difficult or impossible to correct once a shipment is already on its way to the port or airport.