Invoicing, Showback and Chargeback

Invoicing reconciles provider invoices with allocated cost; chargeback moves that cost into team or product budgets using agreed rules, cost categories and shared-cost splits — once allocation is trusted.

Finance needs every invoice explained: which cost centre pays what. Showback shows teams their cost; chargeback actually books it to their budgets.

flowchart LR
  INV["Provider invoices"] --> REC["Reconcile with billing data"]
  REC --> ALLOC["Allocated cost by team"]
  ALLOC --> SB["Showback: report only"]
  ALLOC --> CB["Chargeback: book to budgets"]
  SHARED["Shared costs and credits"] --> RULE["Split rules"]
  RULE --> ALLOC
  %% step INV: Invoices arrive per billing account, often with taxes, credits and marketplace charges.
  %% step REC: The billing data must add up to the invoice; differences are explained, not ignored.
  %% step ALLOC: Allocation by account, tags and cost categories gives each team its cost.
  %% step SHARED: Support fees, enterprise discounts, credits and platforms need agreed split rules.
  %% step SB: Showback creates awareness without moving money — usually the first step.
  %% step CB: Chargeback books costs in each team's budget once allocation is trusted.

Showback first, chargeback later

	Showback	Chargeback
Money moves?	No	Yes, to team / product budgets
Needs	Reasonable allocation	Trusted, near-complete allocation and agreed rules
Effect	Awareness	Financial accountability
Risk	Ignored reports	Disputes if data is wrong

Many organisations stay on showback for a long time; chargeback is worth it when budgets are owned by product lines.

Cost categories

AWS Cost Categories (and similar features such as Azure cost allocation rules and GCP labels in billing reports) map accounts, tags and services into business groups like Teams or Products, and can split shared costs proportionally, evenly or by fixed percentages. The result appears as its own dimension in Cost Explorer, budgets and exports.

Decisions to agree with finance

Which metric is charged: amortized/effective cost (common) or billed cost.
How commitment savings are shared: by usage (teams benefit) or kept centrally.
How credits, refunds, support and tax are handled.
When the books close (data can change for a few days after month end).

Traps: starting chargeback with 60% allocation (endless disputes); charging billed cost so one team pays an upfront commitment that benefits everyone; and changing split rules mid-year without telling finance.