If you have a Thai resident visa and usually live in Thailand but you cannot return within the required year, the Thailand authorities will grant you an extension to your compulsory return deadline. You must return to Thailand as soon as you can.
You need a valid visa to stay in Thailand. If you do not have a valid visa you will have to pay overstay penalties. You should speak to your local Immigration Office or visit the Thai Immigration website.
You are legally required to have a valid passport in Thailand. If your passport expires, your visa will become invalid . If you need to renew or apply for a new British passport, see Overseas British passport applications.
If you cannot renew or change your visa and are not able to travel to the UK (because the border is closed, for example) contact the British Embassy in Bangkok.
Thai authorities may introduce further measures in response to COVID-19. You can monitor the latest updates from Thailand’s Ministry of Public Health website.