An ISP is something like a long distance phone company, in that it gives subscribers access to a long distance communications network. Both the ISP and the long distance carrier incorporate local phone connections in their overall network. Both pay the local phone company for, in effect, reselling the capacity of the local phone network. But they pay different rates. The ISP pays the same rate as any business that uses the phone network to make local calls.
Access charges are much higher than local phone rates, as high as five cents per minute.
Access charges originated in the early 1980s as an FCC-sanctioned way for long distance service to subsidize local phone service. In 1987, well before the Internet became popular, the phone companies wanted the FCC to apply access charges to enhanced service packet data networks like Telenet and Tymnet, but Congress objected, and everyone lost interest in the issue. Now, with the rise of Internet telephony, the phone companies are at it again. They want their subsidies. The current expectation is that the FCC will overhaul access charges in the 1997-'98 time frame.