TalkTalk said its core earnings for the year would be towards the bottom of its expected range of £270-300mln as it restructures the business in an effort to increase its share of the market in the second half of the year.
TalkTalk has been trying to reinstate its standing as a budget internet provider after its reputation took a hit from a cyber attack in 2015, which saw the personal data of more than 150,000 customers stolen.
The company added 46,000 customers in the first six months of its financial year, compared with a drop of 29,000 in the same period last year. It added 46,000 subscribers to its network, compared with losses of 29,000 in the first half of previous year, although lower prices reduced its average revenue per user.
TalkTalk said its broadband base grew for the third successive quarter and customer churn, the rate at which people leave for rivals, had improved year on year from 1.5% to 1.3%.
The company took a £59m exceptional charge for costs including £20m associated with "implementing changes to the group's organisational structure under the new leadership team".
Chief executive Tristia Harrison also said that the firm was delivering on promises made earlier in the year: "When we simplified and reset the business in May we said our priorities were growth, cash and Ebitda [Earnings before interest, taxation, depreciation and amortisation] in that order", she said.
Harrison said the firm had achieved this despite "an uncertain economic environment". The mobile customer base fell by 61,000 in the first-half as TalkTalk prepared to launch a new proposition.