When making use of VoIP (Voice over IP), careful consideration needs to be made as to how you would make a call to the emergency services if the VoIP service is not working for some reason or other.

In the past, a standard landline phone could be used to make calls as it would be powered from the exchange and still work if your premises had a power cut. With VoIP this is not the case. VoIP services are also far more complication and involves various devices both at the service provider and at your premises to all be in working order. This is very different to having a simple analogue telephone plugged in to a socket in the wall.

What could stop VoIP from working?

The following are scenarios that could make your VoIP number from A&A not work:

Power cut in the local area - your internet connection and devices would lose power and not function
Fault with internet connection - could be caused by any number of reasons, an internet connection is dependant on a large number of things working, which could break and take some time to get fixed
A fault with your equipment - eg a router or telephone stops working for some reason
Fault with the ISP or the VoIP provider - Faults can happen.

The main thing:

Ensure you have tested that you can make phone calls in the event of your internet connection being disconnected. Suggestions on how to do this are below.

Suggestions

...for a local power cut

See our VoIP_Power Page

...For faults with the internet connection or VoIP service

Use a mobile phone - ensure you have a mobile or two charged up and with a working service.
Have a backup connection Having more than one connection to the internet is important, not just for calling emergency services. A second line, tethering to a mobile, a service that uses a different medium to your main connection (eg satellite) will help keep your internet connection resilient in case of a fault.

... for using 999 BSL - Emergency Video Relay Service

Access to 999 BSL, to make a video call, requires an internet connection, the service provides an Android/iPhone app, so in the event of a problem with your internet connection using your mobile provider's data connection will give you access. More details at https://999bsl.co.uk/

...if you have poor mobile phone service

Without an internet service and without a mobile phone service extra planning would need to be done to ensure calling emergency services is possible.

Have a UPS (Uninterruptible Power supply) which can power your internet equipment - router, phone, etc so that you have backup power to devices that will enable to you make calls. Test that this works!
See if there is a public telephone box in the area, that works.
See if there are any local shops or petrol stations that would let you use their phone in an emergency - remembering not all shops are open 24 hours.

Other suggestions and help

ISPReview has a page about backup power options here: https://www.ispreview.co.uk/index.php/2021/12/solutions-for-battery-backup-of-fibre-broadband-and-voip-phone.html