You can use the service in most countries, but bear in mind that some don’t allow encrypted data to be sent over a public phone network. If you’re in doubt, check with the relevant consulate or embassy before using the app outside the UK.
The Barclaycard app is free to use in the UK, but your mobile network may charge for mobile and internet use abroad. The app is free to download and available from the app store for iOS and Google Play for Android devices. You need to be 18 or over to use the app. T&Cs apply.