Back in August, popular messaging service WhatsApp introduced an update to its policies and T&Cs that allowed it to share more user information, including phone numbers, with parent company Facebook. Unsurprisingly, most people weren’t happy about the change.

In the UK, Facebook has just agreed to “pause using data from UK WhatsApp users for advertisements or product improvement purposes," after the Information Commissioner’s Office (ICO) contacted the social network to express concerns over the practice.

The ICO wants Facebook and WhatsApp to explain better to customers how their data is used, something that both companies have not yet agreed to. The regulator also warns that Facebook will face “enforcement action,” such as fines, if it uses the data without valid consent.

"We're pleased that they've agreed to pause using data from UK WhatsApp users for advertisements or product improvement purposes," information commissioner Elizabeth Denham wrote in a blog post. "If Facebook starts using the data without valid consent, they may face enforcement action from my office."

When it first introduced the changes, WhatsApp gave users 30 days to opt out of the sharing. But this wasn't good enough for privacy groups in the US, UK, and across Europe, which were quick to investigate the policy.

“These updates comply with applicable law, and follow the latest guidance from the UK Information Commissioner’s Office,” said a Facebook spokesperson in a statement. “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.”

There’s no way for WhatsApp users to stop their phone number from being shared with Facebook, but the company does provide a way to opt-out of having it used to improve “ads and product experiences.”

It’s not clear how long Facebook intends to keep the suspension going, but don’t be surprised if privacy regulators in other countries start taking a similarly tough stance against the new data sharing policy.