NPA-NXX - 510-300

This is the 510-300 subcode (NPA-NXX) prefix page. Follow a prefix to find the number you are looking for. We divide our pages up to make them more user friendly to navigate!

1. Area Codes
2. 510
3. 510-300

The 510-300 subcode mainly covers Hayward in Alameda county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of California state. Many of the numbers in this subcode are Regular Landline registered to U.s. Telepacific Corporation. We hear they employ a large number of people in the California office.
Recently there have been an increase in reported calls, we've had over 1510271 comments across our systems for the 510-300 subcode.