How should I manage two UK passports while entering Thailand and applying for a Chinese visa?

Use the one you have a visa for. Depart on the passport you arrived on.

??? Why

Does this sound = Not legal

Or if it is

NOT a smart thing to do

Serns like WHEN you get questioned about

?why do you have 2 passports

It's likely not going to end well

Just do exactly as you mentioned,, in and out with your Thai visa passport,, you will only be asked at checkin desk to show both as they’ll want to see your china visa and your Thai entry when you leave for china,, I’ve been in/out Thailand for 16 + years on a near monthly basis using 2 Uk passports.

For immigration

you won’t need to show 2 but anyway no issue showing 2 passports, other than occasional confusion, they cannot confiscate your passport,

I asked them on entry one time if they could switch stamps (multi reentry and extension ) to my other passport which they did no issue.

I had an issue once at a land border years ago when my wife mistakenly gave the minivan driver both my Uk passports to pass to immigration along with hers and kids PP’s on entering with a new visa in my passport 😆, was removed from minivan but resolved quickly.

As stated elsewhere show both passports at check-in desk but enter/leave Thailand on one with Thai stamp. That is all immigration are wanting to see in Thailand. Flight is different sometimes they ask to see both other times it is the one with visa for final destination.

I had two UK passports for years. Only leave Thailand on the one you came in on.

Airline and immigration is 2 different departments. Airline only care if u have the visa so they let u fly.

So you can. Learn something every day. Thanks

Just get the Chinese visa in passport 1. Problem solved.

Wow that’s a different one. The passports will be linked via biometrics but almost certain to raise eyebrows.

My guess is that you’d need to enter and exit using the passport 1 that has the DTV visa linked to it. You can show passport 2 to the check in desk to confirm that you have a valid visa for china on departure.

Much like a person with two different nationalities can switch passports mid flight to enter via their preferred method.

I have two british passports and do this all the time. You can use both at check in, explain this is one for visa of country you are going to and this is one with my Thai visa. At immigration only show the one you entered country on.

(Sometimes they want to check valid Thai stamps at check in. Not often but sometimes)

It's perfectly legal for you to have two passports, even from the same country. You use the one with the Thai visa to enter and leave Thailand, and the other one to show when checking in for your flight

Use passport 1 with the immigration. Just show passport 2 when you check in for the flight so the airport staff see you have the correct visa. They won’t be looking for Thailand stamps or care if you have two passports.