The appointment, which follows Red Letter Days' split with Mother earlier this year, is expected to lead to a more consistent advertising presence throughout the year by the company, which has traditionally spent most of its budget pre-Christmas.
Red Letter Days' decision, made without a pitch, comes after Barrett Cernis had pitched for the business when it was originally awarded to Mother. It follows discussions between agency and client on the direction of the brand and its advertising.
It takes place against a background of intensified competition in the "experience" gifts market, with rival offerings available from Virgin, Waitrose and WH Smith.
With origins in the corporate hospitality market, the company has expanded into the high street as the provider of packages through Selfridges, Debenhams, Allders and House of Fraser as well as selling direct from brochures and via its website.
The first work from Barrett Cernis is likely to appear in the autumn.
Media buying remains with Equinox.
Justin Cernis, the managing director of Barrett Cernis, said: "Red Letter Days has always been the market leader but it has to reinforce what it is and what it stands for."
He added: "Although the market has some seasonality, there's no reason why people can't be encouraged to buy at other times of the year."