I went to do a replacement on Amazon (item faulty) and I got notifications from both Monzo & Starling. One was for £1 an the other was an Active Card Check (Monzo was the latter).
Assuming both transactions/checks were the same, I’d have thought that it would deduct £1 from each account.
That bit I don’t know… I’m guessing there is something in the information sent to Monzo when they check the card? Maybe someone geekier might be able to answer that?
Also when you do a add a card to PayPal or android pay, maybe when they company does a check they leave a certain ref (like a regular PayPal transaction will appear as “PayPal 575755” ) so maybe monzo have worked out the patterns?
This is something I noticed recently when adding my Monzo to my PayPal account.
I’ve also had Active Card checks done on my Monzo in the past, temporarily taking a monetary amount (iTunes comes to mind as one). So I’m not sure if it’s something that they always pick up on or not, or if it’s just a more recent feature. (I’m sure someone here could shed some light on that)
I do like the Active Card check notification though it was a welcome change
They seem to catch it sometimes like @airzy91 said. I’ve had a Now TV 10p one this evening that wasn’t caught for example. Uber is always caught though