US tech giant Microsoft has pledged to store all European cloud-based client data in Europe amid unease over the reach of US legislation on personal data collection.

Microsoft's European clients have long been concerned over the legal status of data they store with US companies in the cloud and the extent to which they could be scrutinised by US authorities.

Those worries came to a head last July when the European Court of Justice struck down the EU-US Privacy Shield, a framework allowing firms to transfer personal data to the US in compliance with Brussels' General Data Protection Regulation.

The court found the mechanism did not adequately protect EU data from US authorities over which Europe has neither control nor right of redress.

In a blog post today, Microsoft president Brad Smith said: "If you are a commercial or public sector customer in the EU, we will go beyond our existing data storage commitments and enable you to process and store all your data in the EU.

"In other words, we will not need to move your data outside the EU," he added.

He said the commitment - dubbed the EU Data Boundary for the Microsoft Cloud - would apply across all of Microsoft's core cloud services - Azure, Microsoft 365, and Dynamics 365.

It would take effect by the end of next year, the Microsoft president added.