No phone so need a number unobtainable tone.

[C0pper]

Due to a high volume of nuisance calls we have unplugged our phone. However friends tell us it still rings as if connected. However can I get an NU tone applied to my line?

[Mark39]

@C0pper I don't think you can. You still have a phone service and the ringing tone is generated at the exchange, so so far as Openreach is concerned, the line is still active.

You might want to consider using the Sky Talk Shield as an alternative to unplugging the phone. That would allow approved callers to get straight through, while others are required to say who they are before being referred to you. 9 times out of 10 they'll just hang up. 

https://www.sky.com/help/sky-talk/sky-talk-features/sky-talk-shield/articles/sky-talk-shield-getting...

[Daniel0210 · Accepted solution]

@C0pper 

I'm not aware of that being something Sky can/will do. Why don't you use Sky Talk Shield or use a handset with built in call monitoring and blocking. 

I have a Panasonic handset that basically stops probably 99% of unwanted cold calls getting through.