Upvote:1
This is allowed under UK Immigration Rules App V s4.3 https://www.gov.uk/guidance/immigration-rules/immigration-rules-appendix-v-visitor-rules Funds, maintenance and accommodation provided by a third party. However, you will have to prove to the ECO that you have a genuine personal relationship with your friend (eg provide details of when and how you met, evidence of regular communication etc). Even with a sponsor you will still have to demonstrate your financial capability, and your friend will have to prove that he/she can fulfil the commitment to support you (eg provide bank statements/payslips, permission from landlord to host you if relevant). See the sections on Sponsorship Issues and PLAB Refusals in this question UK visa refusal on V 4.2 a + c (and sometimes 'e')