Hey Scotty, apologies for the disappointment and confusion here, we definitely need to communicate this more clearly in the app and beyond! The fact we promote the Monzo card as great for travelling (FX free spending and competitive Mastercard exchange rates) could in some cases give the impression that the card is available to customers internationally. The last thing we want to do is mislead people with our offering, it does nothing but leave those new to Monzo with a poor introductory experience 
Informing people at the sign up stage will make more sense than rigid technical controls as a solution; you only need a UK address to sign up, not a UK phone number.
Whilst the focus is on launching as a bank in the UK this year, we do want to work towards expansion internationally at some point. We’ll most likely start to explore this once we’ve found our feet as a regulated bank and all our UK customers have access to the Monzo current account, so it could be a couple of years until you see us in NZ!