csearle wrote:Skipped a few posts so hopefully not duplicating but I use contactless almost all the time for almost everything; have never had a single payment booked twice (especially as my Monzo account makes a "ka-ching" noise from my phone as it releases funds); and have never bothered with a receipt.
I think that if I ever did have a dual payment I'd go back to the seller showing my phone with its transactions and ask for a repayment. Can't see this ever happening though.
But in answer to the DAK question: simply use Monzo. You know whether it has taken money instantly because the phone makes the "ka-ching" noise whilst it is still pressing up against the contactless reader.
Chris
PS My phone usually informs me of payment before the seller even knows.
Most posts in this thread seem to be missing the point, as id the thread title. Title should be (something like) "How to confirm if a contactless payment has NOT worked".
As you say, the phone notifies near-instantly when the transaction completed. The problem in the OP is slightly different though, being how to satisfy oneself that a failed transaction really did in fact, fail when the notification did not arrive, and the spotty spod on the till is demanding one tries (and perhaps pays) a second time.