transactionId
The unique identifier for a transaction, such as an In-App Purchase, restored purchase, or subscription renewal.
Declaration
string transactionIdDiscussion
The App Store generates a new value for transaction identifier every time the subscription automatically renews or the user restores it on a new device.
When a user first purchases a subscription, the transaction identifier always matches the original transaction identifier (originalTransactionId). For a restore or renewal, the transaction identifier doesn’t match the original transaction identifier. If a user restores or renews the same subscription multiple times, each restore or renewal has a unique transaction identifier.