Coin line phones were typically offered by the local telecommunication companies, and they required special line equipment at the Central Offices.

These pages are still under construction and 3-slot pay phones will not be discussed here any time soon.

A great paper to read to understand the (electrical) principles of coin line phones: Operation of traditional coin telephones by Douglas A. Kerr

Single-slot payphones (placeholder)
3-slot payphones (placeholder)

(the last payphone in Ahwatukee AZ, operated by Qwest and later Wimactel, decommissioned in 2020).