Declines (Automatically blocked)
Some merchants automatically block prepaid cards. The ones we are aware of are
- Lyft
- Pay at Pump petrol pumps
- Parking Meters
- Arriva and Cross Country (onboard purchases)
- West Quay Multi Storey
- Swan centre top car park
Other Issues
- TFL ticket inspectors cannot currently read the card using their existing terminals. If you explain you tapped in and it is a known issue which TFL and Monzo are jointly investigating, you should be fine. If you do get fined, we will of course refund you the money.
- Uber works for some users but not others. Uber’s official stance is that they do not support prepaid cards but some Monzo customers have reported that it works for them. We are working with them to try and resolve this.
- Uber payments show up incorrectly in feed (we are working on a fix for this)
- TFL Cycle Hire is a little temperamental and has been known to decline payment.
- Transactions at NCP Car Parks appear in the app but are followed by an immediate refund.
- Manchester Metrolink, Bodmin Service Station appear to decline contactless transactions - chip and pin should go through fine.
- Pin accepted but payment refused at St Andrews Car Park Norwich
We’d appreciate you sharing any other declines you’ve encountered when using Monzo. It would be equally helpful to hear of any vendors listed above which you have made successful transactions with 
We’ll keep the pinned post updated regularly & will do our best to work with these merchants to get Monzo unblocked, but any contacts you have would also be very helpful 
Related Threads
TfL Revenue Inspection Fails [Prepaid Beta]
Using Mondo for pay at pump petrol
Card declined at Car Park payment machine in Basingstoke