Originally Posted by email2markt

Hi,
I couldn't find anything online so thought i'd share some of the things I had to do to get an online seat selection on China Southern with a booking via a travel agent.

App
- The app can be changed to English by pressing the little pin at the top left and changing the country to your country. The pin is only available on one of the tabs and you need to hide a toast notification to be able to see it. Any pop-ups, press the blue button and not the white one.

Website:
The website differs depending on your region. These instructions are for Australia.

Seat Selection and Check-in
- Goto "Online Service" -> "Seat&Check-in"
- Enter your email address and wait for a verification email with the code to continue. (phone number also worked for me)

Certificate No / Ticket No
- Enter your ticket number from your ticket invoice (or credit card statement), it will start with 784, you should remove all dashes. eg 7841234567890
- I think it is always 13 digits long. Note that if you have a few flights in your itinerary, you may have different ticket numbers for different segments, so in this example your first 3 flights might be 7841234567890 and your 4th flight might be 7841234567891, they're usually sequential.
Surname
- Yep, surname
Given Name
- All your given names, but remove the spaces between them. So if your name is John Simon Smith, your given name is JohnSimon
Flight Number
- I didn't need to add extra zeros, so it was just CZ123 (not CZ0123)
Date
- Departure date

Tip: If you can't access the seat selection for just one of your flights, proceed with one of the flights that you can and then press the More Seats button from there, the form looks identical except it actually works.

Hope this helps someone reduce my 25 minutes of hacking down to maybe only 5 minutes. If anyone knows any better ways then I would be very keen.