If we authorise the estimated fare amount on your bank account during your first order and you cancel it to try again, we will not authorise again another amount on your credit card and use the existing one which will remain on hold for a short period of time.
Therefore in practice, you should not have to authenticate again if you try to order again for the same destination. Of course, should you hail for a totally different destination, the estimation will change and we would have to adjust the amount of the temporary authorisation which could lead to another identity check.