NatWest is to run an eight-week pilot of an app which calculates customer carbon emissions as they spend.
The UK bank is inviting customers to join the trial, which will use technology from fintech firm CoGo.
The app will provide trial participants with access to a tracker that calculates their carbon footprint in real time based on their spending habits.
CoGo also suggests hints and tips on how to reduce your footprint, like switching to renewable energy or buying second-hand clothes.
Earlier this year, NatWest built a carbon calculator to help staff understand the environmental impact of working from home during the Covid-19 pandemic and to give tips on how they can cut their footprint.