Hello Rachel, thanks for posting on this thread, currently HMRC is down at the moment until Thursday, that is why you are getting that message. HMRC have a status page where you can view current issues or updates to their services, you can have a look at this link it tells you more about it here. You can also subscribe to their updates at that link so you can get notified of any planned works or if there was an emerging fault with their services. Any questions at all feel free to ask them here.
