The fibre box (ONT or Optical Network Terminal) that's installed in your home requires power to operate.
This means your internet and phone services will not work in the event of a powercut. This includes emergency calls to 111. To stay connected, you'll need to use your mobile phone.
If having uninterrupted services is important, you could consider installing a backup battery device that will ensure your phoneline and router stay operational. If you'd like some information, get in touch and we can help you out.