Sadly, a no update update. It’s September 2021 and the border is closed for most. This effects tourists, business visitors and most normal people, including all Hong Kong residents.
If you want to visit China you must apply a visa – even if you hold a valid multi-entry visa or an APEC card – a new visa must be applied. Depending where you enter you most likely get two week hotel quarantine. That mean two weeks you can’t leave your room!
In the latest news visitors from Shanghai and Guangdong may soon be able to visit Hong Kong without quarantine. And there is some talk going on about quarantine free visits from Hong Kong to Shenzhen.
This said, the 5-Day-Shenzhen-Visa seems far away though and is unlikely to happen to happen in 2021.
