Yes indeed, but in my case the Dect base station and master phone sit very close to my router. However, I wanted the
flexibility of using my own router if I chose to do so, and that's now more tricky. I have a Netgear D7000, it does not have VoIP, but we could argue that an alternative router would be better than the D7000 or indeed the SR203 may be better at some level.
I do recall "accepting" a condition wrt the Talk Anytime terms, but I
assumed these were generic conditions alerting you to the fact that VoIP requires the broadband service and power, i.e. cannot be relied upon for emergency calls. Since I had no choice in this selection, I incorrectly assumed that my regular PSTN line would continue to work as was the case for every supplier up to now. I don't think I can change anything from my side, or my account on the Sky portal.
There is a silver lining here too: calls with the VoIP service seem to have no 'noise' or crackles, kind of expect total silence with a digital service, and this sometimes annoyed my wife to death

!
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Tony