Short answer: first make sure enough time has passed, since Apple adds at least 24 to 48 hours before a postback. If none arrive after that, check that the app registers the install by calling the SKAN update method on first launch, and that the ad network is set up in the publisher app.
Why postbacks go missing entirely
SKAN postback: the signed message Apple sends to an ad network, and optionally a copy to the developer, when an install is attributed to an ad.
Apple only sends a postback when an ad was signed for SKAN, the user installed within the window, the app was launched and the install was registered. A break at any of those steps means no postback.
Is it a delay or a real failure?
If test installs are less than 48 hours old, it is probably delay. Apple says the minimum time from impression to postback is 24 to 48 hours. A testing profile reduces that to 5 to 10 minutes, so use one to separate delay from failure quickly.
Likely causes
- Still inside the random delay. Apple's minimum is 24 to 48 hours.
- The app never registers the install. Apple's guidance is to call the update method on first launch.
- Ad network ID missing from the publisher app. Apple requires the ad network's identifier in the publisher app's Info.plist.
- Outside the install windows. Apple allows 30 days to install after a StoreKit-rendered ad, 24 hours after a view-through ad, and 60 days after install for the first launch.
- No first conversion update in time. The device has 60 days after install to send the first update.
How to confirm it
- Wait at least 48 hours after test installs before concluding anything.
- Install an Apple testing profile and repeat the test for a delay of about 5 to 10 minutes.
- Check your code or MMP SDK for the SKAN update call on first launch.
- Ask the ad network to confirm its SKAN network ID is present in the publisher apps it buys.
- Check whether a developer copy of the winning postback is set up in your Info.plist, so you can see postbacks directly.
How to fix it
- Register the install with a conversion value update on first launch.
- Opt in to developer copies of winning postbacks (iOS 15 and later) to monitor them yourself.
- Re-test with the testing profile after each change.
- Move to AdAttributionKit alongside SKAN as networks adopt it, since Apple now points app ad campaigns there.
| Check | Expected result |
|---|---|
| Time since install | 48 hours or more |
| Update on first launch | Called |
| Network ID in publisher app | Present |
| Install within window | 30 days click, 24 hours view |
The SKAN null values troubleshooter covers postbacks that arrive without values, and the SKAN 4 postbacks guide covers windows and delays. If only the first postback arrives, see only the first SKAN postback.