---
title: sourceAppStoreItemIdentifier
framework: StoreKit
role: symbol
role_heading: Instance Property
platforms: [iOS 14.5+, iPadOS 14.5+, Mac Catalyst 14.5+]
path: storekit/skadimpression/3727300-sourceappstoreitemidentifier
---

# sourceAppStoreItemIdentifier

The App Store ID of the app that displays the ad.

## Declaration

```swift
var sourceAppStoreItemIdentifier: NSNumber { get set }
```

## Discussion

Set this property to the App Store item identifier of the app that’s displaying the ad.

If you’re using a development-signed build to display the ads and not an app from App Store during testing, use `0` as the item identifier.

## See Also

### Creating a signature

- [init(sourceAppStoreItemIdentifier:advertisedAppStoreItemIdentifier:adNetworkIdentifier:adCampaignIdentifier:adImpressionIdentifier:timestamp:signature:version:)](init(sourceappstoreitemidentifier:advertisedappstoreitemidentifier:adnetworkidentifier:adcampaignidentifier:adimpressionidentifier:timestamp:signature:version:).md)
- [version](version.md)
- [adNetworkIdentifier](adnetworkidentifier.md)
- [sourceIdentifier](sourceidentifier.md)
- [adCampaignIdentifier](adcampaignidentifier.md)
- [advertisedAppStoreItemIdentifier](advertisedappstoreitemidentifier.md)
- [adImpressionIdentifier](adimpressionidentifier.md)
- [timestamp](timestamp.md)