Apple, Microsoft and Amazon have agreed to give cloud storage subscribers fairer contracts after intervention by the UK's Competition and Markets Authority.
Such cloud storage services are typically used to store photos, videos, music or digital copies of important documents.
If the services shut down or vary their capacity or prices without notice, customers can lose their data, or be held hostage.
The CMA asked the storage service providers to give adequate notice before closing, suspending or changing services, and to allow customers to cancel their contracts and receive a pro-rata refund if they didn't accept service changes.
The regulator last year obtained similar undertakings from Google, Dropbox and five other cloud storage providers.
The CMA estimates that three in 10 British adults store personal data in the cloud, the majority of them using free services.
The cloud storage providers made the changes to their terms and conditions voluntarily, thus avoiding enforcement action by the CMA. The regulator said it was ending an investigation into cloud storage begun in December 2015.
Amazon's European subsidiary, Amazon Media EU, agreed among other things to ensure that price increases do not take effect during a consumer’s fixed contract term, and to clearly and narrowly define the circumstances in which Amazon may suspend or terminate the contract or service.
Apple subsidiary Apple Distribution International said it would give consumers 30 days to remedy "non-material" breaches of contract before their service was cut off, and would allow them to cancel within 14 days after renewal of a fixed-term contract.
As for Microsoft, it said it would provide advance warning if it intended to shut a OneDrive user's account for going over their storage allowance, and generously promised not to shut OneDrive accounts for inactivity as long as they were fully paid up.
That last will come as a relief to anyone using their OneDrive account to back up infrequently changed data.