My mums house deeds are in my name, can I add my two brothers names on it. The house is owned outright and is currently let out.

Is your mothers name on the deed too? If so she will also need to agree. Why do you want to do this, the deed change must be reorded to be official.

My mums house deeds are in my name, can i add my two brothers names on it. The house is owned outright and is currently let out.

Let me guess: You live in the U.K.

What do you mean "deeds"? Is there more than one house?

If they are in your name, why do you refer to your "mum's house"? It would be your house. If this is true, sure: you can transfer ownership from your name to those of you and your brothers. Why would you think it possilbe that you could not?