In a post on Friday, US President Trump said he wanted an interest rate cap on credit card debt to begin on 20 January.  It follows his proposal for a 10% interest cap in his presidential campaign. The post referred to the public being ‘ripped off by credit card companies charging interest rates of 20 to 30%.  This Post considers whether Trump’s proposals could work in making US households better-off, and whether there could be any read across to the UK.