Mettle is the free mobile bank account by NatWest built for the self-employed Mettle's designed to give you the freedom to run your business. It's built for small businesses, startups, limited companies and sole traders with UK residency. We believe there is something different about people who start their own business – a unique spirit that sets them apart. A blend of drive, ambition and self belief – people who have mettle. So we’ve built an app that embraces that spirit – one that our customers can rely on and makes managing finances as fast and simple as possible.