# Restoring Purchases

Provide a **Restore Purchases** button (for example in your settings screen) so users who reinstalled your app or switched devices can regain access to their non-consumable and subscription purchases without paying again.

## Trigger a restore

```swift
@MainActor func restoreCompletedTransactions(
    completion: ((Result<Void, OnsidePaymentQueueRequestRestoreError>) -> Void)?
)
```

```swift
func restoreTapped() {
    Onside.defaultPaymentQueue().restoreCompletedTransactions { result in
        if case .failure(let error) = result {
            print("Couldn't start restore: \(error)")   // .loginDiscarded
        }
    }
}
```

{% hint style="warning" %}
The `completion` argument is **required** — pass a closure or `completion: nil`. Like `add(_:completion:)`, the completion only reports the pre-flight outcome (`OnsidePaymentQueueRequestRestoreError.loginDiscarded` if the user dismisses the login screen). Restored transactions are delivered through your observer.
{% endhint %}

## Receive restored transactions

Restored purchases are delivered to the **same** `onsidePaymentQueue(_:updatedTransactions:)` observer method, with a state of `.restored`. Handle them exactly like a purchase — unlock content and finish the transaction:

```swift
case .restored:
    unlockContent(for: transaction.payment.product.productIdentifier)
    queue.finishTransaction(transaction)
```

(See [Making a Purchase](/sdk/purchasing/making-a-purchase.md) for the full `switch`.)

## Know when the restore finishes

After all restored transactions are delivered, OnsideKit calls one of two optional observer methods. Use them to update your UI (e.g. hide a spinner):

```swift
func onsidePaymentQueueRestoreCompletedTransactionsFinished(_ queue: OnsidePaymentQueue) {
    // Restore finished successfully.
}

func onsidePaymentQueue(
    _ queue: OnsidePaymentQueue,
    restoreCompletedTransactionsFailedWithError error: OnsideTransactionsRestoreError
) {
    // Restore failed — show an error.
}
```

### Restore errors

`OnsideTransactionsRestoreError`:

<table><thead><tr><th width="220">Case</th><th>Cause</th></tr></thead><tbody><tr><td><code>.cancelled</code></td><td>The restore was cancelled.</td></tr><tr><td><code>.connectionError</code></td><td>Network failure.</td></tr><tr><td><code>.serviceUnavailable</code></td><td>Server returned 5xx.</td></tr><tr><td><code>.appNotRegistered</code></td><td>The app/install isn't recognized by Onside (HTTP 404).</td></tr><tr><td><code>.internalError</code></td><td>Parsing or other unexpected error.</td></tr></tbody></table>

See the full [Error Reference](/sdk/reference/errors.md).


---

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