Don Greenwood & Associates, Inc.

Houston's 48 security systems listings spread thin across the city rather than clustering in one area. ZIP 77055 and 77060 each hold 4 listings, 77042 and 77074 and 77092 each have 3, and smaller pockets like 77036, 77040, and 77043 carry 2 apiece. That means whoever's near you is likely a short drive away, not across town.

Most entries include a phone number, and a strong majority list a website too, so you can usually call or check online before showing up. None of these listings are marked verified, and this category doesn't have paid placement turned on in Houston yet, so nothing here is labeled Sponsored and the order you scroll through isn't a ranking. If you install or service security systems here and spot a missing phone number or dead website link, you can claim the listing and update it yourself, so someone searching your ZIP finds working contact info instead of a dead end. Call two or three to compare before deciding.