You are aware that pay as you go sims are available from literally every store in the United Kindom, and any child can just buy one within minutes if they are so inclined?
Not to mention that using social media does not require a phone number, and wifi is practically ubiquitous.
>> (Since brexit, that might be different in UK, but I very much doubt it.)
It's crazy that in 2026 when we literally have the knowledge of the entire world at our fingertips it's still easier to just say "I doubt it" instead of looking it up.
To save you those 5 seconds of googling - no, you don't need to present any ID to buy a sim card in the UK.
Not to mention that using social media does not require a phone number, and wifi is practically ubiquitous.