During the same period – which covered the immediate months after the personal data hack hit TalkTalk in October 2015 – BT’s share increased 2.4 percentage points, Virgin Media increased 0.4 and ‘others’ increased 3.5 (although Sky dropped 1.9 ).

Imran Choudhary, consumer insight director at Kantar Worldpanel, said: “Customers have lost faith in TalkTalk as a trustworthy brand. TalkTalk continues to offer some of the most attractive promotions across the home services market and almost a third of its new customers did choose it for this reason, but there can be no doubt that it lost potential customers following the major data hack.” 

TalkTalk also lost existing customers in the fourth quarter of 2015, with 7% of its broadband base leaving for a new provider. BT was the biggest winner, picking up 40% of this lost share.  Nearly a fifth of those leaving TalkTalk did so directly as a result of poor reliability – a significant increase on the previous quarter when fewer than 1% cited this reason.