I will be taking a flight to China and have booked my flight through a third party travel company. They have sent me an email confirming my flight but also requesting that I navigate to a webpage on their site and enter Advanced Passenger Information for the authorities in China. I don't remember ever having to do this for a trip to China before; I believe this has always been done for me when I arrive at the airport.
So my question is: do I need to fill in this information now, or can I wait until I get to the airport and let staff there fill in the information?
I have some concerns which are not entirely related but make me (irrationally?) want to wait; I have to use 2 passports because my Chinese visa is in a recently expired passport and I have a new passport which is now valid. I've not done this before and although I've read online that it will be fine I just want to deal with all passport issues when I'm face to face with someone at the airport.