Does 'contact number' in BrE refer to the act of contacting or to an electrical telephone contact?

It is common in BrE to use 'contact number' where AmE would use 'telephone number'. Does the 'contact' in 'contact number' refer to the act of making contact, or is there a more technical origin, as in the number of a specific electrical contact in the telephone system?

Solution 1:

A contact number can mean "phone number", especially on official forms. "Contact" here refers to the act of making contact. It does not have a (widely-used) specialist electrical meaning.

That said, it's worth adding that I use contact number, and hear it being used, when I am giving someone a phone number that is not my usual phone number but one I may be reached on - "contacted" - due to some temporary circumstance when my usual phone number may not work (e.g. on holiday, a business trip or staying with someone).