# Add a tip

Add a predefined tip or a custom tip to a Tap to Pay on iPhone sale using the CoreTip object.

**Prerequisites:** [Authentication](/api/authentication) · [Run a sale](/guides/payments/tap-to-pay-on-iphone/run-a-sale)

If you want to add a tip to a sale, you can [add a tip that you've predefined in the terminal](#add-a-predefined-tip), or you can [add a custom tip amount](#add-a-custom-tip).

**Note:** A sale can include only one tip at a time. If you assign a predefined tip, it replaces any tip amount that you previously set, including a custom tip amount.

<a id="add-a-predefined-tip"></a>
## Add a predefined tip

You can use the SDK to add a tip that you've already set up in the terminal. Your predefined tips are available in `terminal.settings.tipListArray`. Each entry is a `CoreTip` with a `tipType` of either `PERCENTAGE` or `FIXED_AMOUNT`. You don't need to carry out any calculations. Our gateway automatically adds the tip amount for you.

**Note:** `tipListArray` can be empty if there are no predefined tips in your terminal. Check that a tip is available before you select one. To create a tip, go to [Create a predefined tip on the Self-Care Portal](https://support.payroc.com/en_US/self-care-portal-transaction-management/create-a-predefined-tip-on-the-self-care-portal).

In your app, let the customer choose which tip to apply to the sale. The following code selects the first tip in the list:

**`Swift`**

```swift
if let tips = terminal.settings.tipListArray, tips.count > 0 {
    sale.tip = tips[0] as? CoreTip
}
```

**`Objective-C`**

```objectivec
sale.tip = [[WTPSTerminal singleton] getSettings].tipListArray.firstObject;
```

The following example runs a complete sale with a predefined tip:

**`Swift`**

```swift
guard terminal.getDevice() != NODEVICE else {
    return
}

let sale = CoreSale()
sale.amount = 42.00
sale.transactionInputMethod = TAP
sale.orderId = "YOUR_ORDER_REFERENCE"

if let tips = terminal.settings.tipListArray, tips.count > 0 {
    sale.tip = tips[0] as? CoreTip
}

terminal.processSale(sale)
```

**`Objective-C`**

```objectivec
if ([[WTPSTerminal singleton] getDevice] == NODEVICE) {
    return;
}

CoreSale *sale = [[CoreSale alloc] init];
sale.amount = [NSNumber numberWithDouble:42.00];
sale.transactionInputMethod = TAP;
sale.orderId = @"YOUR_ORDER_REFERENCE";

sale.tip = [[WTPSTerminal singleton] getSettings].tipListArray.firstObject;

[[WTPSTerminal singleton] processSale:sale];
```

<a id="add-a-custom-tip"></a>
## Add a custom tip

You can use the SDK to add a custom tip that's specific to each sale. The SDK accepts only an amount for a custom tip, and doesn't accept a percentage. To specify the value of the custom tip, use `addTipWithAmount`. The following example adds a tip amount of $5.00 to a sale:

**`Swift`**

```swift
sale.addTip(withAmount: 5.00)
```

**`Objective-C`**

```objectivec
[sale addTipWithAmount:@5.00];
```

The following example runs a complete sale with a custom tip:

**`Swift`**

```swift
guard terminal.getDevice() != NODEVICE else {
    return
}

let sale = CoreSale()
sale.amount = 42.00
sale.transactionInputMethod = TAP
sale.orderId = "YOUR_ORDER_REFERENCE"
sale.addTip(withAmount: 5.00)

terminal.processSale(sale)
```

**`Objective-C`**

```objectivec
if ([[WTPSTerminal singleton] getDevice] == NODEVICE) {
    return;
}

CoreSale *sale = [[CoreSale alloc] init];
sale.amount = [NSNumber numberWithDouble:42.00];
sale.transactionInputMethod = TAP;
sale.orderId = @"YOUR_ORDER_REFERENCE";
[sale addTipWithAmount:[NSNumber numberWithDouble:5.00]];

[[WTPSTerminal singleton] processSale:sale];
```