It would be great to do similar to Monzo in explaining the reason for decline.
I left my phone at home (Tymit has location alerts on) and tried to use my card (the shop below my apartment) but it failed. I tried again with the PIN and that failed.
Monzo would let me see why that transaction declined (wrong PIN, incorrect CV2, expiry etc…). It would be great to have this in Tymit too.