If you are a international students in the UK and within a short time you expecting to extend Tier 4 Visa please check the UKBA website. From October 2013 Tier 4 Case Workers are gonna have extra power to refuse Tier 4 Visa extension application if student They think cann't speak a standard level of English even if you have TOEIC or IELTS Level B2. So its really getting tougher for Tier 4 students who's already in the UK. But if you are really good in English then you do not need to worry. My suggestion would be send application before the new rules apply in October. Wish you all the best