Inconsistent use of slashed zero?

Hello!

That's a very astute observation! Yes, it is an intentional decision to use a slashed zero in some fields. Slashed zeroes can help legibility in some circumstances, especially passwords where the number "0" could easily be mistaken for the letter "O". Credit card numbers and CVV share a lot of attributes with passwords; however, I couldn't find an explicit reason that we choose to use slashed zeroes here. It is an intentional decision not to use them in text fields (e.g., notes).

Do you have a preference for one or the other? Would it improve legibility for you to use slashed zeroes in the expiration and phone number fields?

Thanks so much for your feedback. Cheers!