3 ways to detect iCloud Private Relay traffic and prevent fraud

Apple’s iCloud Private Relay is making it harder to rely on IP-based signals for fraud prevention. If your traffic suddenly includes a spike in Apple IP addresses or your geolocation data seems off, this feature is likely the reason. It’s changing how traffic appears and challenging traditional models that depend on accurate network data. 

Here’s what Private Relay does, why it complicates fraud detection, and how you can adjust your approach while still respecting your users’ privacy.

What is iCloud Private Relay and why should fraud teams care?

iCloud Private Relay is Apple’s privacy feature that hides a user’s true IP address and location when they use Safari. It works by encrypting traffic and routing it through two relays:

• The first relay, run by Apple, strips out identifying information.
• The second relay, operated by a third-party partner, assigns a new IP address that’s geographically close to the user.

This setup means no single party can see both who the user is and where they’re browsing. Unlike traditional virtual private networks (VPNs), Private Relay usually keeps users within their region instead of bouncing them to a different country. The end result? Your website sees a generic Apple relay IP, not the user’s real one.

For fraud teams, this means a surge of visitors whose IP addresses and locations are masked. The old tricks — like using IP geolocation, blocklisting risky regions, or linking sessions by IP — suddenly don’t work as reliably. If you don’t adapt, you risk flagging good users as suspicious or letting fraudsters slip through the cracks.

Why does Private Relay break traditional fraud models?

Let’s get specific about the pain points:

• Masked location: Users appear to be coming from Apple relay servers, not their actual city or country. IP-based geolocation checks become unreliable.
• Shared IP addresses: Multiple users can share the same relay IP, making IP reputation scores almost useless.
• Attribution confusion: Linking sessions or identifying multiple accounts from the same user is much harder when the IP address is constantly changing or shared.
• False positives: Legitimate users using Private Relay might trigger fraud alerts simply because their traffic looks different from your historical data.

If your risk models rely heavily on IP-based signals, expect more noise, fewer signals, and a lot more guesswork.

How to detect iCloud Private Relay traffic

Here’s how to spot Private Relay traffic before it messes with your fraud models.

IP range detection

Apple publishes the IP ranges used by its relay servers. By maintaining an updated list of these IP addresses, you can flag incoming requests as likely Private Relay traffic. Be sure to regularly update your list because Apple frequently changes these ranges, and monitor both IPv4 and IPv6 addresses while keeping an eye out for new relay partners or regions.

Behavior-based detection

Spoofed Private Relay traffic often behaves differently than the real thing. Watch for sessions with multiple IP changes (Relay IPs are usually stable), Relay IPs paired with non-Apple browsers, or login patterns that don’t match normal user behavior. These inconsistencies can reveal fraud attempts that basic IP checks miss.

Device intelligence and Smart Signals

IP checks only get you so far. Device intelligence is where you actually get reliable answers.

Fingerprint is a device intelligence platform that uses 100+ device, network, and behavioral signals to assign each visitor a unique visitor ID. Fingerprint also provides 20+ Smart Signals that help you detect spoofing techniques, bots, and more.

For iCloud Private Relay specifically, Fingerprint’s VPN Detection Smart Signal is the heavy lifter. It doesn’t just tell you a VPN is in use, it distinguishes between classic VPNs and relay services like iCloud Private Relay using the relay detection method. Here’s what that looks like:

"vpn": {
  "data": {
    "result": true,
    "confidence": "high",
    "originTimezone": "America/New_York",
    "methods": {
      "timezoneMismatch": false,
      "publicVPN": false,
      "osMismatch": false,
      "relay": true
    }
  }
}

When relay: true, you know the traffic is coming through a service like iCloud Private Relay, not a standard VPN. This lets you treat relay traffic differently from traditional VPNs in your risk models.

Fingerprint’s Smart Signals, like Bot Detection, Virtual Machine Detection, and Browser Tampering Detection, further enrich your risk models. These signals focus on the behavior and characteristics of the device, not just its network address.

Treat relay and VPN traffic differently

Not all anonymized traffic is equally risky. Private Relay usually keeps users in their home region, while VPNs can relocate them anywhere. Adjust your scoring and responses accordingly. 

Blocking all Private Relay users is a terrible idea. It frustrates legitimate users and does nothing to stop determined fraudsters. Instead, use step-up authentication or additional verification only when other risk factors are present.

If you need to ask users for extra verification, explain that it’s due to privacy features like Private Relay, not because you think they’re doing something wrong. Clear communication keeps your support inbox from overflowing with confused (and angry) users.

Keep fraudsters out without locking out your users

iCloud Private Relay is changing the game for fraud and risk teams. The old IP-based playbook is on its way out. The good news: device intelligence — especially with platforms like Fingerprint — lets you adapt, detect, and respond to anonymized traffic without blocking legitimate users.

The key is to build flexible, multi-layered detection systems that can tell the difference between someone using privacy features for legitimate reasons and someone trying to hide malicious activity. As privacy tools become more common and more sophisticated, the teams that keep up will be the ones who keep fraudsters out and keep their users happy.

Curious how device intelligence and Smart Signals can help your team? You can start a free trial or get in touch with our team for a closer look at how this works in practice.