UPDATE 24 Sep '20: 5G eSIM has now launched on O2. You'll need a 5G and eSIM compatible device.
O2 is excited to announce that customers can use eSIM technology on the iPhone 11, 11 Pro and 11 Pro Max, as well as the iPhone XS, XS Max, XR and the Google Pixel 3 and 3XL from 19 September 2019.
O2 customers need only pop into their local store or call customer services to request a new eSIM pack. You can then download an eSIM profile and swap your current plastic SIM card over to your new eSIM profile following the normal SIM swap process.
Customers will still have the option to use a traditional plastic SIM card should they wish.
We have a dedicated eSIM help & support page here, with many Q&A's.