签证函是什么？
“visa letter”或"visa endorsement"， "visa reference number"是国外雇主给申请人的邀请函，内容一般包括对申请人基本情况的介绍、对工作内容和大致的薪酬福利的介绍等。 不同国家的政策不一样，现在大部分发达国家已经不再接受由国内公司发给海外申请人的Visa Letter了；但亚洲的一些国家（比如韩国）还是接受的。
一般来说，申请者需要将Visa Letter连同其他申请材料一起递交到移民局的受理机构。 如果申请材料齐全，并且符合移民局的要求的话，那么移民局会给Visa Letter注明的号码核发签证。当然，这个号码只是代表签证的申请已收到了，不代表批准。 VSA (Visa Sponsored by Australian Sponsorship). This is when a company gives you an offer of employment which then allows you to apply for a visa through your sponsor， i.e. the company and not on the basis that Australia as a destination country needs more workers in this particular field. So technically it's not a work visa， but an emigration one. The company has obtained work rights for you from their Home Office or equivalent department. You are now free to come over here and work. It does help if they have an agreement with the government so that it doesn’t take too long because most people would prefer a direct route where there aren't many hoops to jump through rather than some other way round， like a general skilled migration visa. Most companies want to avoid having any red tape at all unless absolutely necessary. And sometimes even then. They don't want any hassle， especially not with Immigration. Not least 'cos they often get told off by clients who go to other countries and find themselves being waited upon hand and foot instead of shunted around departments trying to sort out visas！ For someone going directly here on a sponsored visa I can give details afterwards about what they need to do next， whether they will be expected to attend an interview or how much money they expect to pay. For example， maybe they should wait until after they arrive before applying for Permanent Residence status等等. But really only once everything else is sorted first！ That depends entirely on the situation. Some employers have nothing to do with immigration matters whatsoever， whereas others spend hours arguing every point of procedure with them． Sometimes， even though it might seem quite simple， these agencies insist on making things harder just in case somebody tries to pull something on them！ Basically， try to make sure you know exactly why