O2 refunds 140,000 customers after overcharging them - what you need to know

When you leave a mobile provider, the company provides a final bill setting out any remaining fees and charges you have to pay before your account is closed. But according to telecoms regulator Ofcom, between at least 2011 and 2019, an error in the way O2’s systems calculated final bills meant some pay monthly mobile customers were billed for certain charges twice.

More than 250,000 customers were billed incorrectly, amounting to £40.7 million in over charges with around 140,000 of these customers actually paying the extra charges, amounting to a total of £2.4 million. O2 has separately been fined £10.5 million by Ofcom for the failings. 

Check out our Best Sim Only Deals guide to make sure you're on the right deal if you're thinking of switching.

If you've not had a refund, contact O2

Ofcom says O2 has refunded affected customers it's been able to reach, in full, for the extra charges they paid, plus an additional 4% in interest. This includes customers who may have since switched provider or closed their account.

But for those customers O2 has not been able to contact, the company has committed to make a donation to charity covering the amount those customers were overcharged by. It has also changed its billing processes to prevent this issue from arising again.

Any customers with evidence they were affected by these billing errors, such as having the same charge twice on your bill, but have not yet been refunded, should contact O2 directly. You can call O2 on 0344 809 0202 or contact it via live chat.

A spokesperson for O2 said: “We are disappointed by this technical error and sincerely apologise to customers impacted."