Report budget status regularly, even when things are on track. When you spot a potential overrun, present options: reduce scope, extend timeline, or increase budget. Never surprise stakeholders with a cost overrun.
Strong answers cover: regular budget reviews against actuals, earned value management or simpler tracking methods, early warning indicators for budget overruns, communicating variances to stakeholders with options, and contingency reserves. Best candidates discuss the relationship between scope, timeline, and budget trade-offs.
Tests financial discipline. PMs who do not track budgets closely may be well-organised on timelines but miss financial warning signs. Ask: "What is the earliest you have detected a budget issue and what did you do?"