DON'T confuse LATAs with NPAs! The are NOT always identical, not even in California!
The landline-originating dial plan from NON-overlaid California NPAs (as well as New York State, and at least northern Illinois) is:
Same or "home" (intra) NPA Calls: "straight" seven-digits, with NO consideration of local vs. toll status. Toll can be intra-LATA toll as well as inter-LATA toll.
1+ten-digits *IS* permissive for such calls. It MIGHT be (but I don't know for a fact) that SOME service providers require a 1+ and then ten-digits for toll calls even within the same area code.Calls to OTHER NPAs require 1+ten-digits regardless of local vs. toll status of that call. That call can be intra-LATA local, intra-LATA toll, or inter-LATA toll.
The landline-originating dial plan from OVERLAID NPAs in California (310/424 since Aug.2006, 714/657 starting Sept.2008, and 818/747 sometime in 2009 or 2010, and future overlays as implemented), as well as from within New York City's area codes (all overlaid: 212/646, 718/347, and both regions overlaid with 917 as well), and from at least northern Illinois' overlay NPAs (847/224 since 2001/02, 815/779 and 631/330 since
2007), and any other future overlays in NY State and at least northern Illinois as implemented, is 1+ten-digits for ALL calls in the North American Dial Network, regardless of local vs. toll status of that call.I seem to think that when central Illinois 217/447 overlay and soutern Illinois 618/730 overlays are ulimately implemented, local calls (including to those points in adjacent area codes/states, along a border) will be dialable as "straight" ten-digits, without the 1+ required, but the 1+ will be PERISSIVE. A 1+ will be REQUIRED (before ten-digits) for ALL toll calls to any point within the North American Dial Network, whether the same or co-overlaid area code, or to different area codes/ regions.
The reason is that northern vs. southern Illinois developed to some extent with different switching and dialing requirements historically.