The agency search is being run through Creativebrief and will not involve incumbent agency Drum, the Omnicom content shop, which has declined to pitch.
Drum created last year’s "Just another day" campaign which was credited with an 82% increase in regular donations for Age UK, as well as its highest ever haul of donations and volunteers on a single day.
The charity and agency also won gold and silver Media Lions at Cannes last year for the "No-one should have no-one at Christmas" campaign featuring TV and film stars James Bolam and Miriam Margoyles.
Kathi Hall, head of content strategy and brand (charity) for Age UK, said: "We are reaching the end of our contracted term with our current creative agency and we will be reviewing this over the coming months. Our media-buying will still be done by Manning Gottlieb OMD."