A Coronavirus Immigration Team has been set up to help with individuals affected by travel restrictions associated with coronavirus (COVID-19).

There is guidance on http://www.gov.uk regarding individuals who are in the UK legally, but whose visa is due to, or has already expired, and who cannot leave because of travel restrictions related to COVID-19. They will not be regarded as an overstayer, or suffer any detriment in the future.
A visa will be extended to 31 May 2020 if an individual cannot leave the UK because of travel restrictions or self-isolation related to coronavirus (COVID- 19). Individuals must contact the Coronavirus Immigration Team email to advise of their situation.

The Coronavirus Immigration Team contact details are:

Email: CIH@homeoffice.gov.uk
Individuals should include the following in their email:
Full name (include any middle names) o DOB(dd/mm/yyyy)
Nationality
Existing visa details
Reason that has required them to extend their stay (for example, the
suspension of all flight to their place of permanent residence)

The email must be in English.

Telephone: 0800 678 1767 (Monday to Friday, 9am to 5pm) Calls are free of charge.
The Coronavirus Immigration Team will update relevant details on UKVI databases. Individuals will be advised that UKVI have noted their details; they will not be subject to enforcement action; and this period will not be held against them in future applications.

This requirement to contact Coronavirus Immigration Team applies to individuals of any nationality whose leave expires between 24 January 2020 and 30 May 2020.
Individuals who cannot leave the UK due to travel restrictions or self-isolation and wish to stay in the UK in the long-term would ordinarily need to apply for a visa from their home country.
Where individuals would normally be required to return to their country of residence to apply for a visa in a different category, they’ll now be able to apply from the UK to switch.
Individuals will need to be switching from/to a published eligible route and will need to meet the same visa requirements and pay the same application fee.
This includes those whose leave has been auto-extended to 31 March 2020.
Applicants can apply online as usual and select a biometric submission appointment to attend if they are able to in line with public health guidance. We will process applications as quickly as we can but there are likely to be delays due to Covid-19. The terms of their leave will remain the same until their application is decided.
Individuals will not be regarded as an overstayer or be subject to enforcement action if they are unable to attend a biometric appointment due to Covid-19 or if there are delays in processing your application.

Please check http://www.ukvcas.co.uk for up to date advice on UK Visa and Citizenship Application Centres.

Further information regarding Tier 4 students and Tier 2 and Tier 5 workers is available at: gov.uk/guidance/coronavirus-covid-19- advice-for-uk-visa-applicants-and-temporary-uk-residents