If you are using an iPhone to access a mobile boarding pass, you can optionally use the “screenshot” feature to save a copy of your mobile boarding pass to the phone. You can then use this copy throughout your journey, without an active internet connection.
You can do this as follows:
If you are traveling outside your home network, or in a location with poor data coverage, you can take advantage of a lower-cost or reliable network – for example at a hotel, or in your home or office – to access and save your mobile boarding pass before you start your journey.
Users of other phones with the ability to take a screenshot can also use this function to save their mobile boarding pass – please refer to the instructions for your device or application.