Source:Extending your UK visa
'If you don’t want your UK study experience to end just yet, you may need to extend your student visa. You’ll need to pass the points-based assessment to do this, gaining points for proving you have a place on a UK course and enough money to pay fees and everyday living costs.'
Find out more about the points-based system in Applying for a student visa .
The cost of applying for a visa extension is £357 by post or £565 in person, plus £50 per dependant. You can find out if you are likely to have enough points before you apply by using the points-based calculator at the UK Border Agency (UKBA) website.
Proving your student finances
If you apply for a visa extension to complete your current UK course or to study a new one, you’ll need to prove you can cover your costs. You will be asked to provide evidence that you can pay the course fees (only the first year if the course is longer) and two months’ worth of living costs. Your application should be made within four months of finishing your previous course.
If you’re about to complete a UK course of six months or less and want an extension for further study within one month, you’ll also have to provide evidence of your finances. You will need to show that you can pay the course fees, plus monthly living costs, up to a maximum of nine months.
Extend your visa to re-sit exams
In the unlikely event that you need to re-sit an examination or repeat a part of your course, you can do so twice for each exam or module. If your existing visa ends before you’ve finished the re-sit or repeated the module, you will need to extend your visa. Your student support officer at your place of study can help you to make sure all the arrangements are made in plenty of time.
You can find more information about extending your student visa on the UKBA website.