Notifications from Facebook and Instagram have been pinging to users' phones, asking if they want to pay £3.99 a month for their platforms - or continue to use them for free.
So what are you paying for? Essentially, it's to get rid of personalised ads.
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We knew the subscription was coming after Meta, the owner of Facebook and Instagram, announced it in September.
But if you've also just received a notification, here's what you need to know when deciding whether to pay...
How much is it?
Subscribers who use the Facebook or Instagram app will pay £3.99 a month to remove ads, while those who use the web version will pay £2.99.
Meta said the app was more expensive due to fees charged by Apple and Google through their purchasing policies.
These charges apply per account. Additional accounts are charged a £2 per month for web and £3 a month for app.
Who is getting the notifications?
Meta said it was notifying UK users over the age of 18 that they had the option to go ad-free.
You get the notification when logging into your account or opening the app.
It will be dismissible at first to give you time to think about your decision, but will then require you to select an option before continuing.
What happens if you don't subscribe?
If you decide not to sign up, you will continue to see personalised ads.
You will still have the option to set your ad preferences in the settings, which allows you to influence the adverts you see and the data that's used to choose the ads that appear.
Meta has made it clear it does not sell your personal data to advertisers.
Why is it introducing the subscription?
The changes come after the UK's data watchdog, the Information Commissioner's Office, published guidance for companies about ad-free subscriptions last year.
Meta said it would give people a "clear choice about whether their data is used for personalised advertising, while preserving the free access and value that the ad-supported internet creates for people, businesses and platforms".
The advertising model, known as "consent or pay", acts as a way for digital platforms to generate revenue from users who decline to be tracked across their services.
Some news outlets have adopted the model, asking people to accept cookies to access their site or "reject and pay".
(c) Sky News 2026: Why are some Britons getting £3.99 messages from Facebook and Instagram?
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