Author: Tom Kemp
Published: Dec 02, 2025
Understanding Mobile Advertising IDs and DROP
Starting January 2026, Californians can use CalPrivacy’s Delete Request and Opt-out Platform (DROP) to request deletion of their personal information held by data brokers. By entering just a few pieces of personal information, DROP can match it to records stored in data brokers’ databases so it can be deleted. And the more personal information a consumer provides in DROP (e.g., email addresses, phone numbers, etc.), the more likely their data will be identified and deleted across more registered data brokers.
One type of personal information that Californians can enter in DROP is their devices’ Mobile Advertising IDs (MAID). A MAID is a unique identifier (ID) assigned to a specific device, such as a smartphone or smart TV. Because one person typically uses a phone, data brokers can use these IDs to track your habits and location and then monetize that data by selling it to other businesses.
This blog post will help you understand what a MAID is, how to find it on your phone or device, and how to enter it into DROP so it can be matched with data held by data brokers. It will also discuss the advantages of resetting your MAIDs so your devices can’t be tracked moving forward.
What is a MAID?
A MAID is a unique, user-resettable identifier assigned by a device’s operating system (iOS, Android, etc.) to a mobile device to help advertisers track and personalize ads. It also lets platforms and data brokers link app activity, location, and behavior for ad targeting, measurement, and cross-device attribution. Apple refers to its MAID on iOS as the Identifier for Advertisers (IDFA). Google refers to its MAID on Android as the Google Advertising ID (GAID).
Finding your MAIDs to Enter Into DROP
On most Android phones you can find the advertising ID by going to either Settings > Privacy > Ads or Settings > Google > Ads. Samsung devices use Settings > Security and privacy > More Privacy Settings > Ads. Since menus differ across models, the reliable method on any device is to open Settings and use the search bar to look for “ads,” or “advertising.” You’ll see your MAID under “your advertising ID”. Copy that down.
On iOS, you can’t see the IDFA directly in iOS Settings because Apple doesn’t make it visible to users. You can download third-party apps that can display your MAID by searching for “IDFA” in the Apple App Store. Be sure to consult trusted sources and reviews to pick the best app for you.
Consider Resetting your MAID
You should also consider resetting your MAID because it breaks the persistent tracking link that advertisers, data brokers, and apps use to build long-term behavioral profiles of your device. Resetting your MAID makes it harder for businesses to connect your past activity, location history, and app usage with your future behavior. It’s a quick way to reduce targeted advertising, limit cross-app tracking, and strengthen your privacy alongside submitting data deletion requests to data brokers via DROP.
On Android 12 or newer, find your advertising ID as described in the section above.
On iOS, go to Settings → Privacy & Security → Tracking. Toggle off “Allow Apps to Request to Track” to block IDFA access. You can also go to Settings → General → Transfer or Reset iPhone → Reset Advertising Identifier. This regenerates a new random IDFA.
The Network Advertising Initiative provides directions on how to reset MAIDs on connected TVs.
Preparing for DROP
The more personal information, such as MAIDs, you add to DROP, the more likely it is that your personal information will be deleted from data brokers.
As we look forward to DROP’s release, CalPrivacy will continue providing consumers with tips and tools to operationalize their privacy. Learn more about protecting your privacy on our tips page.