---
title: "What is CGNAT, and why does it complicate IP-based fraud detection?"
type: "faq"
url: "https://docs.spur.us/knowledgebase/faqs/what-is-cgnat-and-why-does-it-complicate-ip-based-fraud-detection"
category: "Fraud & Abuse Prevention"
product: "general"
publishedAt: "2026-09-03T12:00:00.000Z"
updatedAt: "2026-09-03T12:11:07Z"
---

# What is CGNAT, and why does it complicate IP-based fraud detection?

CGNAT (Carrier-Grade NAT) lets a mobile carrier or ISP route many customers' traffic through a single public IP address. That means one IP can represent thousands of different devices and a mix of legitimate and malicious users, which makes IP-based signals alone less reliable — additional context is needed to distinguish individual users sharing that address.