Everything Everywhere, the mobile phone company born from the Orange and T-Mobile merger, will be axing 1,200 jobs.
The move is designed to cut costs and expand profit margins.
According to the company, the job cuts will result in cost savings of up to £3.5 billion and account for 7.5 per cent of the 16,000 workforce.
Everything Everywhere said that although the jobs at high street shops and call centres will not be affected, most of the back office and middle management jobs are likely to be cut before Christmas.
The new job cuts follow the 2,500 cuts that were made at the time of the merger. Since the company has come into existence, around 30 senior management positions have been cut.
Speaking to the Telegraph, CEO Tom Alexander said that, owing to the size of the company and the 30 million strong user base, the company has a golden opportunity to offer the best experience to its users.
"To do that we need to ensure that we are operating with maximum efficiency, effectively serving our two brands while removing any unnecessary duplication from the business and, above all, making sure that we are set up to deliver for the future," he said.