On a disputed invoice, first confirm the rate unit: a $100-looking line from a rate of 100 is actually $1.00. Then compare the invoiced quantity to a manual event count; a big gap with SUM aggregation usually means a property value is inflating the total. Add the missing contract override and void/regenerate rather than editing the invoice.

Context: Official docs (Metronome billing diagnostics reference, metronome-industries org): documents a diagnostic playbook for wrong invoices: compare line item quantities against a manual event count, verify the rate card rate is in cents (a rate of 100 means $1.00), check whether SUM aggregation is multiplying by a large property value, look for missing contract overrides, and check credit balances before assuming overage is wrong.