Virgin Media O2 is investing in its early career scheme with plans to hire around 200 graduates, interns and apprentices this year.
Giganet and Cuckoo are creating 250 jobs, mainly across new customer service hubs spanning the country.
The remainder of roles will cover technology, marketing, talent, HR and finance.
Giganet will also be developing a graduate training programme, building on its existing apprenticeship scheme with Fareham College. Places will be offered to up to 20 graduates over the coming financial year.
Jarlath Finnegan, CEO, Giganet said: “Giganet is growing and these new jobs will help us push forward and bring faster broadband to people at a time when the country is financially hurting.”
Alexander Fitzgerald, CEO of Cuckoo added: “Our company is expanding to every corner of the nation, and we want to tap into the talent we know is all over the country.”