The company has opened a 90-day consultation period after identifying areas of its business where there is duplication across Orange and T-Mobile and its 16,000-strong workforce.
The 11 roles to be cut are in the 130-strong brand and communications team led by Stephen Day, vice-president of brand and communications. There are also 11 communications roles to be cut, reducing the division to 108 staff.
It is not yet clear what levels of seniority the roles are at, but the restructure encompasses all levels below the division's directors, who were appointed at the start of July.
The new structure will introduce some roles covering both brands.
Earlier this week the company revealed its second quarter revenues have dropped 4.8% to £1.72bn despite customers growing 3.4% to 27.93 million.
In July's director-level reorganisation Spencer McHugh, previously brand marketing director for Orange UK, took the new role of marketing director for Everything Everywhere.
Stuart Jackson, previously director of communications for Orange UK, took the role of brand communications director responsible for Orange and T-Mobile external communications, along with reputation management of the brand.
Robin O’Kelly, previously communications director for T-Mobile, moved to the position of corporate communications director.