You may wish to reach out to your card-issuing bank to check on the current status of your card.
Alternatively we would suggest removing and re-adding the card to the app, or to use a different card to see if the issue persists.
You can do so by following these few steps:
1) Tap on the Menu button on the top left corner of the app, this is shown as an icon with three lines.
2) Tap on Remove Card. Your card details will be shown as a confirmation. Tap on Remove to proceed.
3) Tap on the Menu button on the top left corner of the app again
4) Tap on Add Card and key in your card details.
5) Kindly try to book another parking session.
If the above steps did not work, kindly try closing/exiting the app fully and relaunching the app.
Do ensure that both your phone's Operating System (OS) and Parking.sg app are up to date.
You may need to delete the Parking.sg app and reinstall it if the issue persists, to start afresh.
Thank you for your patience and understanding.
We apologise for any inconvenience caused.