Facebook has agreed to “pause” its plan to use data from UK users of messaging service WhatsApp for advertising and product improvement purposes across the rest of its business, after an intervention from the UK information commissioner.

Elizabeth Denham wrote to Facebook in September to express her concerns over a new plan to share more data between the social network and Whatsapp.

When it announced its plans back in August, Whatsapp said it wanted to explore ways for users to “communicate with businesses that matter to you too, while still giving you an experience without third-party banner ads and spam”.

The plans involved using the phone number associated with a WhatsApp account to aid Facebook in targeting adverts on the user’s main Facebook profile. But, Denham wrote, she had concerns that consumers weren’t being properly protected, and that “it’s fair to say the enquiries my team have made haven’t changed that view.

“I don’t think users have been given enough information about what Facebook plans to do with their information, and I don’t think WhatsApp has got valid consent from users to share the information,” she wrote, adding she believes users should be given ongoing control over how their information is used, “not just a 30-day window”.

Facebook has agreed to pause the use of its data for advertising and product improvement purposes, although it will continue to share information for spam fighting. The company says it is holding back from promising any permanent changes for now, partly because of the pressure it faces over data sharing.

Facebook says it has received questions from many European data protection authorities, all with different interests and vary requests for information. It says it wants to avoid inappropriately agreeing specific resolutions with any one particular regulator. But it denies that it didn’t give enough information to users avoid how their data would be used.

In a statement Facebook said: “WhatsApp designed its privacy policy and terms update to give users a clear and simple explanation of how the service works, as well as choice over how their data is used. These updates comply with applicable law, and follow the latest guidance from the UK Information Commissioner’s Office.

We hope to continue our detailed conversations with the ICO and other data protection officials, and we remain open to working collaboratively to address their questions.”

Denham argues that the WhatsApp data-sharing case highlights a broader problem in the technology industry. “Our digital comings and goings create rich portraits of our lives, and vague terms of service when we sign up aren’t giving us the protection we need,” she said.

She wrote that she was particularly concerned that when companies merge vast amounts of customers’ personal data become an asset to be bought and sold.

“We’re seeing situations where companies are being bought primarily for this data, and when it is combined with information the purchasing company already holds, there’s a danger that consumers will have little control as datasets are matched and intrusive details revealed,” she added.