Denied Boarding & Overbooking: Immediate Compensation
Airlines routinely sell more tickets than seats. If you're denied boarding against your will, compensation is due IMMEDIATELY — you don't need to prove any delay at all.
Your rights when bumped
Under EU261/UK261, involuntary denied boarding entitles you to the full distance-based amount: €250, €400 or €600 — plus a choice between a full refund and re-routing.
In the US, DOT rules require up to 400% of the one-way fare (max $1,550) for domestic flights, paid in cash on the spot if the substitute arrival is 2+ hours late.
Volunteering vs. being bumped
If you volunteer to give up your seat, you negotiate compensation directly with the airline (vouchers, cash, upgrades) — statutory amounts don't apply.
Never volunteer if you want the legal minimum: once you accept a volunteer deal, you waive the fixed compensation. Ask for cash, not vouchers.
When compensation can be refused
The airline may refuse only if you were denied boarding for legitimate reasons: invalid documents, safety, health, or arriving at the gate too late.
Overbooking is NEVER a legitimate reason — it's a commercial decision by the airline, and the law puts the cost on them.