📱 Mobile

App Tracking Transparency (ATT)

att · app tracking transparency · att prompt · ios tracking consent · ask app not to track · att opt-in · apple tracking permission

Definition

ATT is Apple's mandatory framework for requesting user consent to cross-app tracking; without an allow the IDFA is unavailable and cross-property attribution is impossible.

What ATT changed

Before iOS 14.5, released in April 2021, apps could freely read the IDFA — Apple’s unique device
identifier — for ad attribution and cross-app targeting. With ATT, Apple made that impossible
without explicit user consent.

The ATT system dialogue is shown once and cannot be triggered again. The user sees:

“Allow [app name] to track your activity across other companies’ apps and websites?”

If they choose “Ask App Not to Track”, the IDFA becomes permanently unavailable to that app, until
the user changes the setting manually.

Consequences for mobile marketing

The average global opt-in rate since ATT arrived is around 30 to 40 per cent. That means
deterministic attribution is unavailable for 60 to 70 per cent of the iOS audience.

Without ATT consent	With ATT consent
SKAdNetwork (aggregated, delayed)	Deterministic attribution through the IDFA
No IDFA-based retargeting	Full retargeting
Limited data for ML ad optimisation	Precise optimisation of acquisition campaigns

For retailers with a mobile app this means less accurate measurement of campaign ROI and a need to
invest in a first-party data strategy.

How to raise the opt-in rate

The key tool is a pre-permission screen: a custom screen inside the app that appears before
Apple’s system dialogue and explains the benefit of consenting.

Tip: state the benefit concretely — “We remember your preferences and show products that suit
you” works better than “To improve your user experience”. Generic phrasing lowers trust.

What raises opt-in:

Showing the request on later screens, once the user has already had value
A specific explanation of what is tracked and why
Native design rather than an intrusive popup

ATT and first-party data

ATT increased the value of your own data: an app’s internal analytics — purchase, view and basket
events — is not subject to ATT restrictions. Personalization built on behaviour inside the app
remains fully available and does not depend on IDFA consent.

That makes platforms working with first-party behavioural data, rather than with IDFA attribution,
considerably more resilient to changes in Apple’s policies.

Frequently asked questions

What happens if the user taps "Ask App Not to Track"?

The IDFA returns a zeroed UUID (00000000-0000-0000-0000-000000000000). The app cannot use the IDFA for attribution or targeting. Apple also blocks other cross-app tracking methods such as fingerprinting, which leaves SKAdNetwork as the only attribution channel for user acquisition campaigns.

When is the best moment to show the ATT request?

The optimal strategy is a pre-permission screen shown before Apple's system dialogue. Explain a concrete benefit to the user — personal recommendations, remembering their preferences. Show the ATT prompt after the person has already had value from the app, never on the first screen.

Does ATT affect an app's own analytics?

No. ATT governs only cross-app and cross-site tracking. Internal analytics — events inside your own app — does not require ATT consent and remains fully available.

How does ATT affect mobile advertising attribution?

For users without opt-in, deterministic attribution through the IDFA is impossible. SKAdNetwork is used instead: aggregated, delayed and limited in the parameters it carries. That reduced the precision of user acquisition optimisation on iOS and shifted budgets towards Android and owned channels.