If you have a sky decoder, a phone or a router plugged directly into a jackpoint, the devices aren't filtered and could cause a static or crackling noise.
We suggest installing a filter on every device that connects to a jackpoint. Try unplugging ALL devices plugged into a jackpoint then pick the phone up again. If you no longer hear a static noise, there's a good chance you need new filters. Give us a call and we can get you sorted.
Jackpoint / wiring issues
Over time, the internal copper wiring inside your home supplying phone and internet to your devices can degrade in quality. This is much more common on older homes that haven't had wiring redone. Try plugging your phone into another jackpoint in your home. If the static noise disappears when the phone is plugged in elsewhere, you may need to get a Now field technician or electrician to check out your home wiring.
To check that its not the handset that is faulty, try unplugging the handset and check another phone.
If the other handset is OK, you may need to replace your phone. Make sure you check with us first, as we don't want you buying a phone if you don't need to. We can also run additional checks on your line and give you good insight as to what's happening.