In the digital-first aviation world of 2026, the best place to ask for an upgrade is through the airline's official mobile app starting 24 hours before your flight. Most airlines now use "automated bid" systems or "Instant Upgrade" offers that are only available during the check-in window. If you are looking for a complimentary upgrade based on your loyalty status, this is processed automatically by the airline’s computer system based on your tier. However, if you are looking for a "last-minute" paid upgrade, you can inquire at the check-in counter or the gate podium. While the "dressed up and polite" method at the gate rarely works for free upgrades anymore due to strict corporate policies, gate agents often have the authority to sell empty premium seats at a significant discount (sometimes called "load-factor upgrades"). Be specific and ask, "Are there any paid upgrade offers available for today's flight?" and be prepared to pay with a credit card or miles immediately, as these seats are often snatched up by savvy travelers within minutes of the gate opening.