Just to clarify, I didn't kidnap this randomly from outside. It found me. It came in through the open front door and was banging on my living room door, it's been 30C for the last few days so we have everything open.
EDIT: Alright after consulting the search engines it seems like an uninjured Fledgling to me. Gonna leave it in the courtyard which is pretty safe (besides neighbour cat possibility) and see how it is tomorrow. Entire internet advice seems to say these birds are still being fed by their parents and are learning to fly.
I put some seed and water down for it though I have no idea if it can use them.
If it looks like its not got anyone feeding it tomorrow then I think it'll be intervention time but for now I'll do what the internet says and "leave fledglings alone".