The National Security Strategic Investment Fund (NSSIF) is the UK Government’s deep tech venture capital fund for national security and defence. Its purpose is to support the UK’s future security and prosperity by backing pioneering start-ups whose technologies have strategic relevance to these sectors. NSSIF invests directly in companies and indirectly through leading venture capital funds, helping to bring private capital into areas important to national capability.

Beyond investment, NSSIF connects high-potential start-ups with government customers so they can trial and refine technologies in real-world settings. This work can accelerate adoption, inform product development and help address mission-critical challenges. The fund also assesses emerging technologies and market trends, providing insight to support strategic decisions and future capability planning.

NSSIF’s work spans investment pathways, portfolio partnerships and guidance for start-ups and investors, including resources on staying secure, government contracting and procurement. The fund reports that its programmes have contributed to technology adoption by UK government customers, attracted private investment alongside its funding, and supported job creation across the UK economy.