Last-mile invoices often arrive as weekly batches: zone rates, failed-delivery fees, and fuel lines mixed into one total. Finance teams then ask for SKU-level precision the invoice never contained.
Choose an allocation basis you can defend: order count, weight, or delivery zone volume. Document the basis once and reuse it so month-to-month comparisons stay honest.
Separate failed-delivery and reattempt fees from core delivery cost. Folding them into product margin hides operational issues that belong with customer service or address quality.
When we build a cost map during a DistSysNet audit, we label every allocation as direct, attributable, or shared. Shared costs stay visible instead of disappearing into a blended per-unit figure that no carrier would recognise.
Perfect precision is not the goal. A stable, explained allocation that matches how you sell through retail, marketplace, and direct channels is enough to decide where recovery and process fixes matter most.