If it's a large company usually the company handles everything. At least if they post people overseas often.
It's harder for people hoping to retire or just take a year off. Then they need to handle everything themselves.
One thing a lot of people move and then end up in shock when things are different. Some people just can't adjust. One guy around here last year was whining about clothing sizes. He claimed he always bought a M in North America so all the clothes here were defective since he needed a XL