TalkTalk customers offered free upgrade after cyber attack

Dido Harding said the upgrade is recognition of the "unavoidable uncertainty" facing customers (Anthony Devlin/PA)

If you're a TalkTalk customer, you could be in line for a free upgrade following last month's costly cyber attack.

The telecoms firm said it will take a hit of up to £35 million from the incident and offered the upgrade to all its customers.

The group said it was making the move in "recognition of the unavoidable uncertainty" customers faced after hackers accessed the details of 156,959 customers and 15,656 bank account numbers.

An upgrade will be available to all customers – even those unaffected by the hack – from December 1.

If you're a customer, you will be able to add one of the following to your existing services with the group: TV content including movies, kids entertainment and sports; a mobile SIM with a monthly allowance of free texts, data and calls; unlimited UK landline and mobile calls; or a broadband health check by experienced engineers.

Chief executive Dido Harding said: "TalkTalk takes the security of customers' data extremely seriously and we are taking significant further steps to ensure our systems are protected, as well as writing to all our customers outlining what we are doing to keep their data safe.

"In recognition of the unavoidable uncertainty, and because we know that doing what is right for our customers will ensure the best possible outcome for the company over the longer term, we are today announcing the offer of a choice of free upgraded services to all our customers."

TalkTalk said it was too early to assess the wider impact of the cyber attack on the business, but estimated the one-off financial cost of up to £35 million including the loss of online sales and services.

The group said "significantly" fewer customers were affected by the hack than initially feared and added that all customer-facing online sales and service channels were back up and running.

TalkTalk had earlier said it may have lost the personal details of up to 1.2 million customers as well as up to 21,000 bank account numbers and up to 28,000 obscured credit and debit card details.

In recent weeks three teenage boys and a 20-year-old man have been arrested by the police in connection with the alleged data theft from TalkTalk.

This is the third time that data from TalkTalk has been hacked in the last 12 months.

A parliamentary committee will now conduct an investigation into the circumstances surrounding the TalkTalk data breach and the wider implications for the security of personal information online.

The group has also created a new bundle of online and telephone security features to boost customer protection.

But TalkTalk's move to appease customers comes after experts at Citi recently warned that the bad publicity and the suspension of its website, which is a key means of selling products to customers, may see it lose around 200,000 accounts by the end of the full year, leaving it with around 4.1 million customers.

Speaking to BBC Breakfast, Harding said she believed customers would continue to trust TalkTalk based on measures taken to step up security.

She said: "Over the course of the last three years we've spent a third more on security and I can absolutely guarantee that going forward we will spend much more again."