The agency beat Tullo Marshall Warren in the final stage of the pitch following a tender process, which took place in May. A third agency is understood to have been eliminated at an earlier stage of the process, which was handled by The Observatory.
Lida has been briefed to handle the company's entire customer relationship strategy, including data strategy and planning, creative development across all brands and the implementation of seasonal campaigns. Activity will run across a number of channels.
Avril Lalani, the head of CRM at Signet, said: "CRM is an important element of the Signet marketing mix."
There was no incumbent on the account, but the company uses St Luke's for its above-the-line activity.