It will now be responsible for developing the consumer strategy and online marketing activity for Vodafone Retail's web presence. The win comes a year after Dare was named the digital agency of record for the mobile giant.
Dare will develop all online advertising campaigns for the retail site, as well as advising on aspects of the online sales process, adding to its present responsibility for online marketing across Vodafone's consumer and enterprise divisions in the UK.
RMG Connect will continue to work with Vodafone Retail, handling work that includes DRTV and point-of-sale.
The appointment comes after Vodafone's decision last December to shift its £47 million advertising account out of JWT - RMG Connect's sister agency - and into Bartle Bogle Hegarty.
Dare was named as Vodafone's first digital agency of record last January, following a pitch against Modem Media and Agency.com.
John Owen, the planning partner at Dare, said: "We're delighted to be working with Vodafone in this area. We hope to make a difference."