英国学生签证怎么延签？
1. 首先，您需要知道自己的CAS号码（Confirmation of Acceptance for Study）， 在UCAS的CAS系统里可以查到； 2. 准备下列材料：
A passport-style photograph (白色背景，35x45mm). 建议直接在签证中心拍摄，会特别快！ 记得拍照时露眉毛和耳朵哦~
B visa application form， 签证申请表在UKBA网站下载
C letter from your University confirming that you have a valid CAS， 学校开具的确认信，一定要包含CAS number、课程名称和时间、学校的地址及联系方式等信息，格式可参考附件模板；
D original bank statement showing at least £780 savings in the account for each month between now and when you start your course， plus another £780 for the first month on your course; or if you are applying with an offer to study on a pre-sessional English programme then show evidence of having saved these amounts going backwards over three months， i.e. March £960， February £1，800 etc. You need to prove that this money is real， not just in your bank – make sure it hasn't been put there by someone else like parents， boyfriend/girlfriend/partner/husband/wife etc... You can only apply from within the UK so you will be asked for your current address as well as your passport details. For further information please see our website： URL. Your money must come directly from your own account and cannot include any funds sent via post office orders， banker’s draft， money transfer etc. It may also come from interest earned on other accounts， but does not count towards proof of settlement / maintenance. Please note that banks could take up to 5 working days to update their records which means that if they confirm that the balance was correct before Wednesday midday on Friday， then it would still not meet the requirement for the week. A statement issued less than 5 working days prior to this deadline has no validity. If you wish to use a joint account， both parties must give permission. In most cases we recommend using a current account rather than a saving account. However， some types of savings accounts do count. To find out whether yours counts please visit the Government’s Immigration Money Page ： www.gov.uk/government/immigration-money#how-to-prove. This page explains how you should