Once you have received your CAS from Imperial, you should be able to start the visa application process. If you need any help on the process, Imperial’s dedicated International Student Support team provide specialist immigration advice to prospective students, with particular expertise in Tier 4 (General) student visas and Short Term Student visas (formerly student visitor visas).

The International Student Support webpages contain lots of useful advice on making a student visa application, including:

When applying for your visa, if you would like to collect your Biometric Residence Permit (BRP) from Imperial's South Kensington Campus, rather than a local post office, please ensure you enter the Alternative Collection Location (ACL) code 2HE497 when asked to in your visa application.