I'll try to keep this both short and clear.
I'm US passport holder. I am currently on 90-day visa free stay in Taiwan. In my passport I have a Chinese visa, which has not yet expired. However, AFTER receiving and using the visa, I received a China work visa/resident permit. The resident permit is now expired. Here's where it gets tricky, the Chinese visa office never cancelled my older visa.
What I mean, is they physically didn't slap a "cancel" stamp on the visa. So by visual inspection it seems completely valid.
Clear so far?
So, no one really knows what will happen if I try to enter China with the visa. Luckily, that's not the point of this post
BUT...what happens when I leave Taiwan, have the exit stamp, and then attempt to enter China on my visa? Taiwan has no way to know the visa might not be valid, so even though they will ask to see my visa to China, I doubt they will have any reason to deny my exit from Taiwan.
1) China allows me to enter. OK. Done.
2) China points out this visa is not valid, and denies me entry.
At this point, I've left Taiwan before my visa is expired, have the exit stamp, but I haven't entered any other country. When China denies my entry, can I just get back on the next flight to Taiwan and still receive another 90-day entry?
Will I forever be stuck in no man's land? Forced to return to the US? Pushed off to HK to sort out this mess?
I'm asking this question mostly out of curiosity for the technical workings and precedent for these kinds of visa issues.
If you just want to reply saying: "Don't do it." or "You're asking for it." Thank you for your concern, but you can save yourself the time. This is for people that are interested in understanding the full extent of visa scenarios.
For any other ideas, thanks for taking the time to share!
And if you do have any ideas how to check the validity of my China business visa.
Edit: I'm a fan of the Kinmen/Xiamen connection. Which possibly complicates things, because they can only put you on a boat back to Taiwan, otherwise they would have to let you in the country, even if it's just to fly out...