Will the one-time verification code by text message work if I have no phone signal?

No - you need a phone signal to receive the one-time verification code. If you haven't got a mobile phone signal you may still be able to carry on:

If you're trying to log in, you may be able to use the card security code (CVV) off the back of your Barclaycard instead.  Then once logged in you can update your mobile phone number in the 'Your details' option at the top. If you're unable to log in using your card security code you will need to call us to update your number and our team will also be able to help you with your query.

If you're trying to reset your details you'll need to call us to do this.

If you're shopping online you'll need to choose a different way to confirm it's you. You may be able to select PIN sentry or if you're registered for the app you can confirm it's you with just a few taps.

Find out more at barclaycard.co.uk/confirm.