OpenAI is giving nine big UK banks, including Lloyds Banking Group and HSBC, access to a new artificial intelligence tool called GPT-5.5 Cyber. This tool is made to help defend national infrastructure by improving cybersecurity for important economic services. The move is seen as an important step in using advanced AI to protect the UK's banking system.

GPT-5.5 Cyber mainly helps banks check old software systems, also known as legacy infrastructure, for risks and possible attacks. It looks for hidden problems and suggests ways to fix them, helping banks update their security without completely changing their systems.

This action follows more online attacks from groups using AI to target financial organisations. The project could become a model for protecting other key areas such as energy and transport if it works well in the banking sector.