When using 4thID with services that require payment, your default payment method is used first.
If you have multiple payment methods, the first one added becomes the default. However, setting a new default is easy.
1. Open the 4thID app and log in
2. Navigate to the Profile icon in the bottom right corner.
3. Tap Account and you'll be presented with the current list of payment methods.
4. Tap on the payment method you'd like to be your default. Once the popup appears, simply select Make Default and that item will then become your default payment method.
5. Note that your default payment method is listed first, and contains the Default label on the bottom right.