Tax system in US

Right now, I work in a consulting bureau. This company does taxation of international executives.

I think it is can be very complicated when somebody lives in US and works in another country. Specially people who work in West Europe!

Think! Every state has its own tax law, after that Federal Tax issue doesn't seem to be easy to handle in some cases and after all these, depends on the country people work in; they have to pay some other taxes as well!

A lady who is tax specialist in US, tried to explain just the US part and I was confused!

There is something named tax return. People can get back a little if they mention all the meals they had in other country (I mean in the business destination country), because it will be a business matter, and also even take out some money if they stay in a hotel and pay taxi. Of course all these won't be because of the business, but they can tell it was a business matter!

Let's go right to another point!
If someone is a trader and has his/her own company, he/she can easily mention the spouse as another part of the company and even mention her/his cost of the BUSINESS trip to get tax return!

It was something new for me, and I was amazed by this tax return business. It is not a fun job to do, but still something everybody should know a bit in this confusing modern world! Specially for people like me who has been raised in a country like Iran that doesn't have a very clear and serious tax system.