How to set up chargeback and showback

The rule of thumb is three to six months of showback before you actually charge anyone. In that period the conversation is about "is this right" instead of "I do not want to pay this".

• Azure resource. Has tags and shows up directly in Cost Management. The easiest one.
• Fabric workspace. Has an owner but no price; the cost sits on the capacity beneath it.
• Copilot user. Has a licence and therefore a price, but no consumption.

These three do not mix by themselves. Accept that your model uses a different allocation key per layer, and write down which one per layer. A model that pretends everything is the same is exactly the model people do not trust.

For existing resources use a modify policy with a remediation task. Expect some manual work to remain: anything created by a pipeline without tags has to be fixed in that pipeline and not in the portal.

• Split evenly across participating teams. Simple, explainable, and unfair as soon as team sizes differ a lot.
• By measured consumption, for example CU seconds per workspace from the Capacity Metrics app. Fairer and much more work.
• As platform cost that nobody gets allocated. Honestly often the best choice for the first year.

The pitfall is not the wrong choice but the absence of a choice. An undocumented key gets re-litigated with every invoice.

Build this as a normal data product in your own platform, not as a spreadsheet. A cost report assembled by hand every month stops being updated after three.