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Deal originally posted April 22, 2012. Deal ends November 1, 2014. Post updated 10/13/14:

Southwest Airlines and Airtran Airways’ three-year merger is almost complete. For over two years, transfers have been allowed between Southwest’s Rapid Rewards loyalty program and Airtran’s A+ loyalty program.

These transfers present an arbitrage opportunity that caps roundtrip award flights at 19,200 Southwest points (the normal cost of a $274 award.)

This is a cool trick that can save you major Rapid Rewards. You can use this trick in conjunction with your Southwest Companion Pass (the best deal in travel).

• How does this 19,200-cap trick work for the next few weeks?
• How far in advance can you book Southwest flights?

Transfers Between Rapid Rewards and A+

Southwest and Airtran have two different loyalty systems. Southwest awards 6 points per dollar of your airfare (Rapid Rewards points). Airtran awards one credit per paid flight (A+ credits). Southwest used to have that system, and its credits still exist in parallel with its points system (Rapid Rewards credits).

All this means that there are a lot of loyalty currencies floating around between the two airlines, and for the next few weeks, you can continue to freely convert between the currencies.

The now allowable conversions between Rapid Rewards and A+:

• 1,200 Rapid Rewards points converts to 1 A+ credit
• 1 Rapid Rewards credit to 1 A+ credit
• 1 Southwest Standard Award (two one ways) to 16 A+ credits
• 1 A+ credit converts to 1 Rapid Rewards credit
• 16 A+ credits can be used to fly two one ways on Airtran, and 16 Rapid Rewards credits can be used to fly two one ways on Southwest.

So what does all this mean, and how can we take advantage of it?

Because there are unlimited transfers between the programs, it means that we can use 19,200 (1,200 * 16) Rapid Rewards points for two free (other than government taxes) one way trips on either airline.

19,200 Rapid Rewards points are worth $274, so if you can find two one ways on either airline that cost more than that, you can profit from transferring.

In today’s environment of sky high fares, finding a roundtrip or two one ways that cost more than $274 is pretty easy, especially since Airtran and Southwest fly internationally to Mexico and the Caribbean.

The Big Restriction

There is one catch. All Southwest flights are bookable with Rapid Rewards at a rate of 70 points per dollar of base fare. Here’s how to book those awards.

Not all flights are bookable as “Southwest Standard Awards,” which is what you can book with Southwest Rapid Rewards credits obtained through these transfers.

Southwest needs to release “Standard” award space on a flight for you to book it with Rapid Rewards credits. (Also, this is a confusing name, since most airlines call this capacity-controlled space “Saver” award space and call the rule-busting award space available for double miles on most or all flights “Standard.”)

Southwest tends to release Standard award space only on the cheapest flights on many routes. You can search for Standard award space on this page. After signing into your Southwest account, click the button that says “Standard Awards Availability.”

I searched for Atlanta to Los Angeles in March to see the Standard award availability picture. There was award space mostly midweek.

It’s not a perfect match, but you can see that the days with Standard award availability highly correlate to days with a $165 or $161 flight.

When to Transfer

You should transfer 19,200 Rapid Rewards to 16 A+ credits to 16 Rapid Rewards credits if there are two one way Southwest itineraries (don’t have to be a roundtrip):

1. that cost more than 19,200 points combined (approximately $274)
2. that both have Standard award space (search before transferring)

The Atlanta to Los Angeles Standard award space from the last example topped out at 9,246 points one way under the normal Southwest award pricing.

Two such one ways would only by 18,500 points under the normal Southwest award pricing. They would cost 19,200 under my trick, making my trick a bad deal for such award space.

How to Transfer

Now that you know when to transfer, here’s how to transfer. It’s incredibly easy.

• Log in to your Southwest account.
• Click on the My Account link.
• Click on the My Rapid Rewards tab.
• Choose the Transfer Between A+ Rewards and Rapid Rewards button on the left side of the page.
• Type in your Airtran account information, then follow the instructions to transfer Rapid Rewards points to A+ Credits (then A+ credits to Rapid Rewards credits if you are booking with Southwest)

This transfer option makes Southwest’s program temporarily much more lucrative. For short cheap flights, the normal points price will remain incredibly low, sometimes just a few thousand points for a roundtrip. For longer, more expensive flights, though, a roundtrip is effectively capped at 19,200 points, so we get the best of both worlds: points-cheap short trips and points-cheap long trips.

How Far Out Can You Book Southwest Flights

Right now you can book Southwest flights through April 6, 2015. Southwest opens up its schedule in chunks. A new chunk may open before this trick disappears on November 1.