Vodafone's 14 million customers will be able to donate monthly by adding £2 to their bill or removing it from their phone's credit, make one-off donations, or donate via the Vodafone website. The company will match every donation.
The charity's chief executive Vernon Beauchamp said that working with Vodafone would help it to extend its services and "realise a world in which autism is recognised and understood by all".
Stuart Notholt, director of policy and public affairs at the society, said Vodafone had invested a huge amount of time, effort and money in identifying the right charity partner. "It has been professional and diligent, carrying out a great deal of research into autism and raising staff awareness, and that has already been beneficial."
Vodafone began looking for a new long-term charity partner two years ago and whittled the candidate down to three finalists.
"We emerged as the one with the best fit," added Notholt. "What swung the decision was that Vodafone is a communications company and we are a charity dealing with a communications disorder."
Vodafone and the society have worked together to determine the kind of specific projects that would be supported.
Some £2m each year will be devoted to policy development and public affairs, where the current budget is £4m-£5m. The other beneficiary is individual donor development.
The deal makes Vodafone the biggest single corporate supporter of the society. "It is going to transform the whole dynamic of how we support people with autism and their families," said Notholt.