Are game download codes transferable?

[ataraxicstorm]

Would anyone know if codes for downloads of games are transferable? I bought a copy of Just Cause 3 download, got a message through from Xbox with a code to download Just Cause 2 for free since I purchased it - but since I already own that game was wondering if the code is linked to my account or if someone else can use it?

 

[MobileVortex]

If the code has not been redeemed yet. You can give that code to anyone.