# Test offline payments

Simulate network failures to test your offline payments integration without going physically offline.

The Terminal SDK includes a `simulatedOfflineModeConfiguration` property that lets you simulate network failures in test mode without physically disconnecting from the internet. Use this to verify your offline payments integration handles connectivity issues correctly.

> You can only use `simulatedOfflineModeConfiguration` in test mode. Setting a non-default configuration while connected to a livemode reader throws a `TerminalException` error.

## Before you begin

Make sure you:

- Have a working [offline payments integration](https://docs.stripe.com/terminal/features/operate-offline/collect-card-payments.md).
- Are operating in [test mode](https://docs.stripe.com/terminal/references/testing.md) with a reader.

## Configure simulated offline mode

The `SimulatedOfflineModeConfiguration` object has two properties that you can configure independently:

- `sdkOfflineMode`: Simulates network failures for calls made by the SDK itself.
- `readerOfflineMode`: Simulates network failures for calls made by smart readers with independent connectivity (such as WisePOS E or S700). This property is ignored for Bluetooth and USB readers because all network calls flow through the SDK for those reader types.

| Mode                   | Behavior                                                                                                           |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------ |
| `DISABLED`             | Default. No simulation. Uses real network conditions.                                                              |
| `OFFLINE_IMMEDIATE`    | Requests fail instantly with a network error.                                                                      |
| `OFFLINE_TIMEOUT`      | Requests hang for 15 seconds then fail. Useful for testing retry and timeout logic.                                |
| `OFFLINE_INTERMITTENT` | Approximately 50% of requests fail randomly. Useful for testing retry behavior and partial connectivity scenarios. |

## Toggle simulated offline mode

#### iOS

```swift
// Enable simulated offline mode
Terminal.shared.simulatedOfflineModeConfiguration = SimulatedOfflineModeConfiguration.fullOffline

// Reset to normal network behavior after testing
Terminal.shared.simulatedOfflineModeConfiguration = SimulatedOfflineModeConfiguration.default
```

## Check reader network status

The `OfflineStatus` object lets you query the current network status of the SDK and the connected reader. You can read it directly at any time:

#### iOS

```swift
let networkStatus = Terminal.shared.offlineStatus.sdk.networkStatus
```

Or use the `OfflineDelegate` (iOS) or `OfflineListener` (Android, Java) to receive updates whenever the network status changes:

#### iOS

```swift
class CustomOfflineDelegate: OfflineDelegate {
    func terminal(_ terminal: Terminal, didChangeOfflineStatus offlineStatus: OfflineStatus) {
        let networkStatus = offlineStatus.sdk.networkStatus
        // Update your UI based on networkStatus
    }
}

Terminal.shared.offlineDelegate = CustomOfflineDelegate()
```

## See also

- [Collect card payments while offline](https://docs.stripe.com/terminal/features/operate-offline/collect-card-payments.md)
- [Test your Terminal integration](https://docs.stripe.com/terminal/references/testing.md)