Stellar acquires Callbase's AI Voice Agent platform for regulated enterprises.
Dutch AI startup Stellar, which builds AI agents for customer service, has acquired Callbase, a voice AI platform for healthcare organizations.
tellar, which builds AI voice agents for enterprise customer support, has acquired Callbase, a voice AI platform for healthcare organizations. The deal marks Stellar’s first acquisition and expands its footprint in regulated industries.
Founded in May 2025, Stellar’s team has grown without funding to nine people and production call volume grew tenfold in Q4 2025.
Stellar’s growth and this acquisition reflect a broader market shift: voice AI has moved from experimentation in early 2025 to production today.
“The market has moved faster than anyone had expected and now the conversations are about rollout timelines and call volumes instead of pilots.”
While the benefits of voice AI for customer support are clear, scaling enterprise voice AI agents to production is hard. Co-founder Dennis de Reus saw this firsthand as Head of AI at ABN AMRO when launching the first voice AI agent in finance globally.
“Getting a voice AI demo to work is the easy part. The real work is to get it to feel natural, stay compliant and hold up across thousands of real calls. That's why we started Stellar.”
Stellar’s clients span multiple sectors: for example Landal in hospitality, NVM in real estate, Vanbreda Risk & Benefits in insurance and 24Rosa in social housing. The Callbase acquisition adds healthcare, another regulated industry, to that list. Clients can expect a seamless transition when moving to the Stellar platform. Deal terms were not disclosed.