I thought I'd post my recent experiences on using an SWU to upgrade from Premium Voyager (Prem. Economy) to Affairs (Biz) on Air France. On cavet: I haven't actually taken the flight yet. According to Air France I am confirmed and have seats in J but until I actually get on the plane there is some small doubt. I was also lucky that I had some flexibility in dates. Originally the trip was going to be an open jaw, LAX-CDG-ZRH/NUE-CDG-LAX but the client I was going to see changed some things at the last minute and it turned into a straight R/T to ZRH. My steps apply if your final destination is in Europe. Some people have reported success in upgrading out of CDG to Asia but others have had problems, so your mileage may vary... It was also easy for me in that I live in a AF gateway city. If you have to fly to one of these it may introduce some additional complexity. I don't know if G/Z spaces needs to be available on any domestic leg, but it wouldn't be surprised. The key is to have researched everything ahead of time and have all your information handy. This is a fairly new thing and my guess is most DL agents (even with PM and DM desk) haven't done one before so you may need to guide them. Some will want to back out at the first snag and say "it can't be done" and you need to (gently) press them forward. Or hang up and try again. I had a good and helpful agent and we managed to get it done in 20 minutes or so. Step 1: Find out which flights have upgrade inventory. I did this with ExpertFlyer.com as I have an annual membership. If you have a Flying Blue membership number you can use that as well. The key is you look for O class -- which AF uses for both straight awards for J as well as upgrades to J. With expert flyer do an award search of your gateway to CDG for O class and write down the dates and flights that work for you. (In my case there are two daily flights and sometimes only one or the other had O) If you don't have ExpertFlyer and using the Air France website, I'm told you look for "Classic" (i.e. "low") awards in Affaires. Step 2: Choose and price your itinerary. You want to do this on AirFrance.us not on delta.com. Choose your cities and dates and from the class drop down choose "Premium Economy." You will get a list of outbound and return flights. Make sure you choose the TATL flights you know have O inventory (from step 1). You can choose the intra-European segment that fits your needs. Click on "validate your segment" and you'll receive a summary page with flights, times and a price. I did a screen print of this so I had it handy or you can just write it down. Step 3: Call Delta. The first two steps were the easy part. This part doesn't take much work on your part, just some patience and maybe some gentle prodding. I called the DM line and said I wanted to buy a Premium Economy ticket on Air France and use my SWUs to upgrade to business. And gave here the cities and dates. She came back and said that their system didn't show any upgrade inventory for those dates. This is the first pitfall -- the link between the two system doesn't seem to be real time. I told her it was there according to the AirFrance website (a white lie since it was ExpertFlyer). And she said something like "let me check using DirectNet" and lo and behold, it was there. I'm guessing "DirectNet" is how Delta agents query the AirFrance system so those might be magic words to use if they claim there is no upgrade inventory. Snag 2 came when she priced the itinerary on Delta's system and it came out to over $6000. Not what I was looking for. I asked "can you price it on Air France's system" and she said "let me see" and there was a minute or so of typing and she said "I got it, $1431.70" (which actually was 30 cents cheap than AirFrance.us -- I guess they round up to the nearest dollar). Snag 3 came right away when she said "I've got the price but it won't store" -- I assume that means that she could save as a PNR and purchase a ticket. I had my screen cap from the AirFrance.us site and we sort of compared things and it turned out she had tried to put in A class for the entire trip and it wasn't accepting that. It turns out A (these are AF codes, not DL) is just for "Premium Voyager" which is specific for long haul flights. The intra-European legs had to be in W, which is "Premium Economy" -- a different beast altogether. That done, she took my credit card number and bought the ticket. She asked if I had any preference on SWU's to use (I had none, they all expire at the same time). She applied those and gave me the Delta and Air France PNR (the latter is important, be sure and get it) and before we were done she said "oh, AF has given you seats" and she gave me the seats numbers (on 3 out of 4 legs -- CDG-ZRH says "gate") When I checked the itinerary on delta.com it doesn't show any seats -- that is my usual experience with KLM (this is my first AF flight since the merger) so I wasn't worried. I went to airfrance.us and put in the PNR (and last name) and up came my rez with the seats she'd read off to me and a big bold "confirmed" in the upper right corner. I changed my seats slightly -- and they saved. (A good sign) Things I am watching: I have an 006 ticket number but none of my SWUs are marked as used -- I guess this is not-uncommon with DL (I've just used PMNW PU503 before and they used those on the spot) so I am not worried -- yet. I gather this means my ticket is still for PV and not for J (hasn't been re-ticketed). If I don't see any change later this week I will call Delta, and then probably AirFrance just to make sure everything is hunky-dory. The Known Unknowns (At least for me -- I recognize some handles of people "somewhere else" that have done similar transactions and they may be able to help here). Domestic home to gateway leg on Delta. Airfrance.us will price this, with codeshares (e.g. AF 8XXX) in their class A, but I would assume that Delta G/Z inventory would need to be available to be upgraded. If it didn't go thru, I'd assume you be high up in your medallion level priority since it is a high fare class. Long Haul past CDG. The rules on delta.com say TATL only. There are reports of people successfully upgrading CDG-BKK with the same SWU used on the TATL leg. My guess is that is only because this is a new thing and all the rules aren't known to everybody. So if you do have experience with this (or hints) please respond to the thread. Can I upgrade LAX-PPT? It definitely is not TATL but it is a shorter flight than LAX-CDG and generally costs more (and least in Y and PV) so who knows. If you are headed that way it might be worth a shot. Let us know how it goes. In theory, PV earns a 25% bonus of RDM and a 50% bonus of MQM which lowers the cent/mile calculations. My nagging worry is that if the "Class Paid/Class Flown" codes get messed up there could be confusion because AF O is both a straight award and an upgrade. But others have reported proper posting so I remain hopeful. Part of me feels this deal is just to good to be true and won't last forever. I don't know how this works with the JV but seems strange that we have a great instrument that can be used on Air France that is better than anything their own members have and also why can we use it on a $1500 AF flight but not a comparable "native" (e.g. DL) flight of similar cost. Can you image the uproar if FB Plat could upgrade, say, "H" fares with miles or an instrument when we can't.