Collective has clients including Microsoft, O2, Sky, Unilever, Disney and eBay and provides digital solutions and brand campaigns across display, video and branded content on multiple platforms.
The agency's managing director, Giles Ivey, said the agency had been approached by a number of companies in the last year and that it had chosen to join Time Inc because of the opportunities to combine the offering of the two firms.
"When we talked to Time Inc we knew immediately that there were so many ways we could work together to produce amazing results for our clients," said Ivey.
"In an era where the ability to offer scale programmatically, to create and distribute content and also to offer experiential solutions is key, we’re so excited to be part of Time Inc and be a part of delivering the highest quality and most coherent brand solutions in the UK market."
Time Inc said the acquisition would support its digital growth initiative, deepen its customer relationships and offer greater opportunities in higher-level ad planning and buying decisions.
Sam Finlay, chief revenue officer at Time Inc UK, said: "Collective UK’s ability to deliver market-leading premium creative solutions for brands at scale further strengthens our market-leading proposition."
Collective UK, which has 47 members of staff, will continue to operate from its London offices on Great Marlborough Street. Ivey, who runs the agency in lieu of a chief executive, will report to Finlay.
Time Inc UK publishes titles including Pick Me Up!, Marie Claire, NME, Uncut and Ideal Home.