Wiring can be extended from jacks or from the junction where wiring enters the home. The rule of thumb is to use the method—or a combination of the two—that results in the shortest run of wire.

Telephone wiring is thin, meaning it is easily routable but also easily damaged.
Because of this, do not run wires nor install jacks:

* Near any source of heat, such as water pipes and air ducts, which can corrode the wiring.

* Within several inches of electrical receptacles, which can cause interference on the phone line.

* In the same conduit or to the same junction box as electrical outlet wires because a short could cause a surge of current to the phone wire.

* Close to bathtubs, sinks, swimming pools, and any other source of moisture (including damp basements), where the use of a phone could constitute an electrocution hazard.

* Too close to large, grounded appliances in a kitchen.