Originally Posted by NickB

Payment total is the value of the ticket rather than the payment taken at the time of issue. If your FTV was of at least the value of the sum shown in red under Payment total, then there was nothing to pay and no additional payment would have been taken other than the FTV voucher itself. If you look a few lines above the one in red, there may be a line which indicates the value of the voucher used. If that value is at least as high as the line in red, then no payment is taken. I do not think that there is anywhere on the e-ticket that actually states what payment was taken when issuing the e-ticket, just the value of the ticket. You can deduce what value was taken by deducting the value of the FTV or eVoucher from the "Payment total". At any rate, that is the way it works on the ticket that I recently paid using an eVoucher as part-payment.