Removing wires for additional phone lines with separate numbers

[MarcusClaret]

About 15 years ago our work situation meant that we had to have two additional phone lines with different BT numbers installed. These appear to have been spurred out of the back of our master socket, with a single wire running up the outside wall into our study where there are two internal plate junctions, one for each number.
Can I simply cut the wire coming out of the back of the master junction box and silicone the point where it comes out to the external wall? if so, is there any chance that in doing so, I will damage our home phone line connection within the master socket?

Thanks for any help anyone can give

[Keith_Beddoe]

@MarcusClaret 

The external network is the property of Openreach, so if you cause damage to the external network cable, you would be liable. If in doubt, contact BT and ask for an Openreach Field Technician to do the work.

[DavidM]

Hi @MarcusClaret and welcome to our community.

Thanks for posting about the wiring. I'd go with @Keith_Beddoe advice on this. Better to be safe than sorry.

Cheers

David