AltFi takes a look at overdrafts in the digital banking market, both arranged and unarranged; their research found that Starling Bank offered the best overdraft product by charging the equivalent of 15 percent; Monzo was the runner up with a 50p charge every day your account is overdraws more than 20 GBP; B from Clydesdale and Yorkshire Banks and N26 rounded out the top four; overdrafts are an important business for banks and offer customers a lifeline when needed, though it can be taken back by the bank at anytime. Source.