tier4签证毕业后多久？
首先，我想强调一下，这个 Tier 4 visa 和上面的那个 Tier 4 student visa 是同一个东西！只是名称不一样罢了！Tier 4 is the UK government's official name for a kind of visa. It applies to both students and migrant workers， but in this case we’re only talking about students. The word ‘visa’ itself means permission to enter or remain within a country (and therefore you don't need one if you aren't planning on leaving)！ So， technically speaking： it isn't called a 'student visa'， because that would imply that its holders are allowed to leave. It doesn't say what they have to do when they get there either; just who can let them onto British soil！ This all might sound rather confusing， so here's an example： Let’s call our character Mr Smith... He arrives at Heathrow airport with his passport filled out properly. At immigration control he tells the officials that he has come over to take up study at a university near London： namely， University of Oxford！ They check everything on his application form looks OK and grant him entry into the United Kingdom as an academic visitor under paragraph C8 of their immigration rules（注意这里并不是给他签一个“学生签证”）， which basically says： “You must be able to prove you were accepted by us before applying； your stay must not exceed six months； and you must leave after you finish studying！ ”. This gives him a kind of legal status known colloquially as "Tier-4".
Now， back on planet Earth… Once again， remember we said that people normally apply for a specific type of Visa depending upon whom exactly and why exactly they want to go？ Well， things are no different for Mr Smith. What he needs right now is something called a 'Certificate of Acceptance from Sponsor'！ This proves that he was issued an offer letter by a registered university. When you receive such an offer， your sponsor should issue you with this certificate along with another document called a Student Record（这两项文件由大学发给学生的录取通知书里自带）. Afterwards， these two documents become your legal evidence of being admitted into Britain. You will then be free to ask for a Tier-4 visa at your nearest British consulate overseas！ There， they will tell you how much money to bring along， where to sit during the interview， whether or not you should wear shoes…… In fact