| 13 February 2021 UK comms regulator Ofcom has fined mobile network O2 £10.5 million after billing errors meant it overcharged customers who switched to another provider. In 2019 Ofcom opened an investigation into potential issues with the way O2 was billing departing customers and found an error in the system. It showed that between 2011 and 2019, more than 250,000 customers were billed incorrectly, amounting to £40.7 million – with around 140,000 customers paying the extra charges, which came to £2.4 million. O2 has refunded the customers affected in full, plus an additional 4%, and committed to making a donation to charity for the equivalent amount of money in the case of any customer it has been unable to reach. It has also changed its billing processes to prevent the issue arising again.