# Identifier for advertisers (IDFA)

Apple's advertising identifier, whose access is subject to platform restrictions including ATT authorization.

Apple's advertising identifier, whose access is subject to platform restrictions including ATT authorization.

## An example

An authorized app measurement flow uses an available IDFA for an eligible attribution task.

## Why it matters

Lack of access is not permission to replace it with covert fingerprinting.

## Reference

[Apple advertising identifier documentation](https://developer.apple.com/documentation/adsupport/asidentifiermanager).


## Related terms
- [Attribution](https://jolts.xyz/resources/glossary/attribution)
- [Device ID](https://jolts.xyz/resources/glossary/device-id)
- [Mobile measurement partner (MMP)](https://jolts.xyz/resources/glossary/mobile-measurement-partner)
- [Privacy thresholds](https://jolts.xyz/resources/glossary/privacy-thresholds)

## Next step

[Explore advertising](https://jolts.xyz/advertisers) or [monetize your AI app](https://jolts.xyz/publishers).