请问申请ssn需要多久？

As long as the SS office approve a card for you, same day or next day. The actual card will arrive in2 weeks. If they do not approve you right away, you might be subject to verification, which means you cannot leave the country, etc. Well, as long as the SS office approves the number, it is already assigned. 在您材料准备齐全后去到当地SS办公室，当时如果立即批准，那么一般您的卡会在两周之内寄到。