We're moving from flat plans to usage-based credits. How do you test it before everyone gets a new bill, and when do you stop?

Shadow-bill everyone first, roll out to new customers before existing ones, protect annual plans and default overage to zero. Set stop rules on bill-shock tickets, refunds and downgrades before you start.

Updated Nov 2026 · Original practice questions with worked answers and teaching rubrics. Our editorial policy explains the sources, review process and limits.