Are we talking profit per customer in the UK or profit for Monzo as a whole - these are very different things?
Unit economics for each customer in the UK has been a key focus for Monzo and they have gone from making a loss on each customer to making a small profit. This, at scale, should make a sustainable business and you can be sure that additional profit lines will be added over time. Head office costs etc are not factored into this I believe, hence the current losses.
Monzo as a business may choose to spend hundreds of millions on international expansion, developing other products etc and so may, at that level, make huge losses. That’s also entirely legitimate.
Revolut are taking huge investments and expanding hell for leather, Starling are taking a more conservative path. It’s always felt to me that Monzo sat in the middle of these two. Either way, showing a profit at this stage in the growth of a business may be missing the point. As long as the unit economics make sense then it is valid to rack up additional losses to get the distribution and expansion up.