Lifetime budget

Lifetime budget is a fixed spend cap for a scheduled flight (start/end dates). Platforms pace delivery to exhaust the budget by the end date — unlike daily budget, you are committing to total spend over the flight. Common for promos, product launches, and TikTok/Meta burst tests.

Underspend at period end means delivery could not win auctions or audiences were too narrow — not always “unused budget to refund.”