What do I need to have in order to get 30 days extension?

You will need to submit your passport, registration form of temporary accommodation, documents to prove that you need to stay longer in China, like travel itinerary, return ticket, hotel bookings.

Yes, you need to be registered at a police station within 24 hours after you arrive in China.

I personally don't think the 30-day visa extension will void your 10-year L visa.

I went to the immigration department today in Suzhou, China. I have a ten year L visa, 60 day stay, multi-entry. My 60 days expired, they gave an automatic extension of 60 days to everyone. After that you have to apply for a 30 day extension which WILL VOID YOUR ORIGINAL VISA. This is directly from an immigration official. I am going to HK tomorrow for a visa run; however, I cannot return to china until they lift the travel ban. The Chinese policy basically forces you to trade your ten year visa for a 30 extension OR forces you to leave China during a time when almost all countries are locked down. Either way, you are hosed.

Thanks for sharing your information.

Hey have you gone to HK by shenzhen? how was it..what happen in the HK immigration as soon as you arrived there, I heard that you will be place in quarentine in a specific hotel chosen by them and then you are able to stay in HK for I believe 90 days as you are a US citizen like me.Could you give me some details, my wechat: DanielVR, Thanks man!

You will be a lucky one if they give you any extension at all. Everyone I know with an L visa is being told there is no extension available and to exit China before the auto-60 day extension expires - or pay the fines up to 10000 and risk being banned from future entry!

*And yes, your 10 year visa will be cancelled when you apply for the new visa extension.