NPA-NXX - 410-423

This is the 410-423 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. 410
3. 410-423

The 410-423 subcode mainly covers Columbia in Howard county. But other numbers maybe included as well.

We have a database of information derived from the public phone records of Maryland state. Many of the numbers in this subcode are Regular Landline registered to At&t. We hear they employ a large number of people in the Maryland office.
Recently there have been an increase in reported calls, we've had over 287085 comments across our systems for the 410-423 subcode.