Tellows

tellows is a German company, based in Leipzig. It provides a platform for an international community to find and share information on phone numbers. The site is active in 50 countries worldwide in their respective languages. Focusing on user experiences and caller behaviour, tellows collects detailed phone number information like caller names, types, evaluation, search history and location which allows a precise caller classification due to up-to-date data. The company provides services to help privates, developers and businesses to identify and block unwanted calls. tellows developed an extensive API that allows to easily integrate its data in different solutions for landline, PBX, smartphone and mobile app. Together with his partners, tellows has developed solutions to fight against unwanted calls, such as the Fritzbox router blacklist, the Gigaset Smart Call Block and many other products for landline and mobile phones. Interested in joining the API partnership program? Visit