Not sure where I should post this but I'm going to be on a Delta flight from DTW to PVG and connecting on SkyTeam partner China Southern to CAN (two separate tickets in economy). Procedure in PVG when transferring is that you have to clear immigration and re-check in your bags. I've done this route twice in the past and haven't had any problems checking in the two bags with China Southern (thought I might due to check-in restrictions on domestic flight is 20kg). China Southern airline staff told me that if you are connecting from a US flight your bags are not subject to that restriction. I wasn't quite sure whether that's true but for my upcoming trip I am going to be checking in 5 bags so will definatley be paying excess baggage charges to Delta so my question is will China Southern charge me again? Again in the past I haven't had trouble checking in two bags but I am not sure I can get away with 5.....

Make sure you get the "excess baggage coupon". It will print out when they charge you (it will be on "green stock"). Sometimes agents just throw them away when that is your way of giving payment to the OAL. BTW it is different the the receipt.

nice...and this will ensure i dont get charged by china southern?

Yes that is correct.

If the coupon mentions that the charge is to CAN, then CZ shouldn't charge you. If they try, you show them the receipt and tell them you already paid DL all the way to CAN. If the receipt only shows PVG, then CZ could charge you.

Yes make sure you check your bags ALL the way through. Be sure to sure your itn and receipt to the TA when checking in.

Is there a chance that Delta won't agree to check it all the way through because I am switching carriers (even though they are part of ST)?

There is always a chance. But the bigger chance, in my opinion, is that DL will only charge you the excess baggage fees to PVG. I have seen that with other airlines across the Atlantic. People think they paid all the way to their end destination, then when they arrive in the US, they are hit with another excess baggage fee. It is crucial to double check that DL is charging you all the way through.

Get to the airport early. You don't want to have to rush the agents through this - they need to manually enter the connecting flight info, etc.

Will do, thanks to both of you...much appreciated!

Wirelessly posted (BlackBerry8520/4.6.1.286 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/301)

At the airport in YYZ waiting for my connection to DTW then onwawrds to PVG and CAN. Fortunatley I didn't have any difficulty in getting all my bags checked in to final destination: CAN. Only thing however, I saw that coupon that was printed out and which the desk agent made me sign, it said "coupon" on it so I immediatley realized that this is what I need to keep. However, the agent refused to hand it over said that this was the only document that Delta had the confirmed my payment of excess baggage. She told me that the receipt indicated that the charge was to CAN and that will be enough for CZ. She was very rude through out the process but then again all of my bags were above 50lbs so I didn't argue.
The receipt says: YYZ DL DTW DL PVG CZ CAN
Hopefully that will be enough..

In my opinion, you made a huge mistake. You have no receipt for something you signed? That is common with any business. You sign something, you ask for a copy and you get it.

Good luck, but I am not hopeful if you have nothing in your possession that shows you paid for luggage to CAN. My guess is that they will try to charge you in China. How will CZ know you paid? You have nothing to show it and I would be surprised if CZ uses the same reservation system as DL.

Hopefully....the agent is completely wrong in not giving you the coupon.

Currently at PVG waiting for my flight to CAN just thought I'd report in to say that the check-in process was as smooth as ever. Took less than 60 seconds from going through the business class check-in counter, able to check-in all of my bags with no questions asked. Although it was quite funny as I was loading my 4 bags the agent asked "how many bags are you allowed to bring from the U.S.?" And I was like "oh 4" and she shrugged it off didn't even care about the weight and didn't have to show my excess baggage receipt from Delta. And as a kicker my bags were tagged as "priority" even though I was in Y and only Skyteam Elite. All in all good trip.

Thanks so much for posting the update. Many people never return to the thread to give an update of how it ended up. Glad to hear it worked out so well for you!