Monzo card declines in California

I did think I had posted a topic on this forum but apparently not as far as I can see. The situation is as follows: I have just returned from San Francisco, LA & Vegas and had no problem using our joint account card in any restaurants or bars. When it came to using it on the BART (SF) & Metro (LA) it just didn’t work and yet my Halifax Clarity card did - odd as they are both Mastercard - anyone care to enlighten me on this one.

I would say the ability to freeze does make me feel more secure and goes what I can now free the Halifax card. Perhaps the big boys are going to take all this seriously.

I know that BART has been identified as an issue previously, see:

This might be helpful. In any event I’d always check the Wiki articles on here prior to using Monzo abroad. There are always quirks it seems.

I found that BART will only take Monzo on some of the machines. I think the ones that explicitly say Credit Card, rather than Debit. I know that is odd as its not a credit card but I think it because of how they process it.

I had no issue with it in LA, so not sure what was going on there.

Selecting debit or credit card in the US refers not to the type of card/account, but which card networks/routing to use.

Visa, MasterCard, Amex, Diners etc are all credit card providers. They use the same networks to process their own branded debit cards which means for example, Visa debit cards run on a credit network to be processed.

Debit card networks refer to smaller, local banks in the US.

Travellers from the UK going to the US almost always are going to select credit as the type on terminals.