Most domestic airlines offers a First Class upgrade FREE to full-coach (YClass) paying passengers (this is commonly referred to as a “Y-UP” fare).
Travelers flying on short notice or who can’t manage a “Saturday-night stay” – or those who are trying to find a seat on a near-full flight and have to pay full-fare anyway - can take advantage of this frequently overlooked option. With an advance purchase, but no Saturday-night stay, you can often find even lower fare levels that offer a Y-Up fare.

For example:
• Northwest Airlines offers both a free upgrade to First Class and 1,000 bonus miles through its “Connect First” program, for travelers paying a full-coach fare, on qualifying routes that make connections through Detroit, Minneapolis or Memphis. You’ll receive a confirmed
First Class upgrade when you book your flight. To qualify, your itinerary must include a change of aircraft and flight number. The upgrade is not available on all flights.
• US Airways also offers a free upgrade to First Class for travelers paying a full-coach fare for many of its transcontinental, Texas and Midwest routes. A free upgrade to first class (known as an“A4Coach” fare), is available in hundreds of markets.
• Delta’s new YDLUP First Class fares replace their existing A06 published fares. They are equal to the applicable Y06 fare, but allow travel in the First Class cabin. The YDLUP fares are applicable in 4,700 markets with connecting service via Atlanta, Cincinnati and Salt Lake City.

• Air Canada now offers upgrade certificates that let you turn your full-fare coach class ticket, booked in Y or M class, into a seat in Executive Class for only $100 CAD ($70 USD) round-trip. This offer applies only on designated routes between the US and Canada.
And you’ll not only be more comfortable, you’ll also be entitled to earn 25% more Aeroplan miles for flying in Executive Class.
Upgrades can be confirmed within 48 hours of departure.

• American Airlines has a published YUP14E1N fare for $957 round-trip for travel between Dallas and Miami – while the published First Class fare is $2,386.
• America West also offers a “Y-Up” fare category allowing for First Class travel for the price of a non-discounted, full-coach class fare. The fare is available in all markets.
So next time you’re considering paying full-fare, make sure to ask your reservations agent if a Y-Up type fare is available for your itinerary. Many seasoned travelers have told me they’ve never even been offered such a
fare. If one isn’t available for your trip, you might check another schedule or airline.