Sweden. I had a long discussion with my former employer about this as they tried to enforce not reimbursing expenses without it. (That didn't go over too well though)

I ended up calling the authorities to get the final say on it and it turns out that according to the law, the company name must be there. The guy I spoke to did admit that if it is plausible that I stayed somewhere for business, it is highly unlikely to cause any problems if the company name isn't there, but technically it should be.