Sandbox Madrid launches its first public call for private sector entities, allowing companies, entrepreneurs, and other entities to test innovative solutions in a real, controlled urban environment.
This call for proposals is aimed at projects related to sustainability, the circular economy, and energy, and will remain open until March 2, 2026, at 11:59 p.m. (Madrid time zone).
What is Sandbox Madrid?
Sandbox Madrid is an initiative by Madrid City Council that turns the city into a controlled testing environment for innovation. Through this initiative, Madrid opens up its urban spaces to test innovative solutions in real conditions, under a regulatory framework that guarantees safety, accessibility, and the general interest.
Under the slogan "The future is tested in Madrid, " Sandbox Madrid is committed to learning by doing: testing, evaluating, and generating useful knowledge to improve the city and its services.

Who is this call for proposals aimed at?
The call for applications is aimed at:
- Companies, startups, entrepreneurs, and private sector entities.
- Individuals or legal entities, domestic or foreign.
- Projects submitted individually or in groups.
Deadline and submission of applications
The deadline for submitting applications will remain open until March 2, 2026, at 11:59 p.m. (Madrid time zone).
Applications must be submitted via the Madrid City Council's electronic headquarters.
Check out the complete rules here and submit your project
www.sandboxmadrid.es