The instant messaging app, which has over one billion monthly active users, announced yesterday that it plans to share users’ details with its parent company Facebook.

According to the company’s blog, WhatsApp wants to “explore ways for you to communicate with businesses that matter to you … while still giving you an experience without third-party banner ads and spam”. Interestingly, the blog also mention that while it plans to share your phone number and some details with Facebook, your WhatsApp messages will be “encrypted by default, which means you're the only people who can read them”.

So what does this sharing of information mean in real terms? Well in short, while you still won’t see any ads on WhatsApp, the ads you see on your Facebook feed will become more targeted and relevant. So maybe you booked a Ryanair flight and had to input your phone number during the booking process. As a result, you might see Facebook ads for things like Ryanair travel insurance and car hire specifically for the trip you plan on taking.

However, while you may see more targeted ads, WhatsApp has insisted it won’t share your phone number with advertisers: “We won’t post or share your WhatsApp number with others, including on Facebook, and we still won't sell, share, or give your phone number to advertisers.”

Luckily, if you really don't want WhatsApp to share your number there is something you can do to prevent it. Firstly, the next time you open WhatsApp and a T&Cs message appears, simply select the ‘read more’ button and uncheck the "Share my WhatsApp account information with Facebook …’ box. If you have already accepted the terms without knowing what they actually meant, you have 30-days to opt out. Simply go to Settings > Account and uncheck the ‘Share my account info’ box.