My mum can phone out but no-one can call her. The phone rings both ends but when answered there's s

[terry.jones]

Broadband checked.  Phones working OK.  Calls from the number are fine but when rung, although the phone rings, when answered there's silence.

[Mark39]

Can she run the connection test here, which will enable her to book an engineer there and then, if a fault is detected.

https://www.sky.com/help/articles/broadband-diagnostic-start

Failing that, the quickest way for her to get help is to give Sky a call (dial 150).

[caesarome]

@terry.jones 

See if your mother can run this line test to see if a fault is found outside of your property and if something is found you can book an engineer repair:

https://www.sky.com/help/articles/fix-phone-problems-start

You can also run this test via the MySky app.

Let us know how you get on.