I know 424 is connected to Los Angeles, but I’m curious which nearby cities or neighborhoods also use it. Is it mostly newer numbers, or has it been around for a long time already?

The 424 area code serves the exact same coastal and Westside region of Los Angeles County as the classic 310. It’s an overlay code, meaning it was added to the same geographical area back in 2006 to handle the massive demand for new lines, so it's been around for quite a while now. If you get a call from 424, it covers cities like Santa Monica, Beverly Hills, Torrance, Malibu, Culver City, and Hawthorne, plus LA neighborhoods like Venice and Westwood. You can look up specific prefixes here to see exactly where a number is registered. Mostly, newer residents or secondary business lines get assigned the 424 digits, while older landlines keep the 310 legacy.