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Plant test number


In landline telephony, a plant test number or exchange is a number or group of numbers reserved for use by telephone installers to perform routine tests on an individual telephone line.

These include, but are not limited to:

Each country uses different codes. BT Linetest Facilities (for example) are available by ringing 17070 and a self-service test facility for subscribers is on 0800 800628.

In the North American Numbering Plan, 958-xxxx and +1-NPA-959-xxxx are commonly reserved for local and long-distance test numbers (respectively). A few localities (including Winnipeg) reserve 959 only.


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