The operator bought the accommodation-only specialist for £21 million amid huge speculation in the bedbank market over consolidation between some of the established brands.
Thomas Cook is currently developing its new e-commerce platform, codenamed Starfish, and is to be released in stages over the course of the year.
The plan is to fully integrate the Hotels4u content into Starfish as opposed to offering it as a white label.
Thomas Cook UK and Ireland director of e-commerce Russell Gould said: “Hotels4u gives us a huge opportunity in the accommodation-only market. It has a fantastic product set and makes ours even stronger.”
The Hotels4u white label went live on thomascook.com in the past couple of weeks.
Gould said: “To say were are pleased with the way things are going is an understatement.”