Guild Wars 2

So I own the core game and I have played a lot of hours. If I buy the HoT expansion in retail will I be able to use (I guess the code for the activation) to my main account or will the code can be used only for the core game that comes with the purchase of the HoT expansion? Also If I will be able to use the code of the HoT expansion for my main account will I also own another copy of Guild Wars 2 core game?

Once you buy the expansion, one of two things are possible.
1) you apply it to your main account. That account will now have access to expansion content.
2) you use it to make a new account that has the expansion.. This will give you a new account with 5 empty character slots, but no direct access to your old account and your old account can not enter the new maps or have any expansion content. You’ll need to make and level completely new characters.

If buy HoT can use code on you account upgrade to HoT. Go to “My Account” link to add HoT code and have HoT expansion. Will not have second account core game.

Thank you guys for your answers!