So, we’re in NYC (amazing) at the minute, my Monzo app wouldn’t open, so after looking here for advice I deleted it and reinstalled it.
Now, it won’t verify my phone number, despite me putting all the verification codes in.
Not great when I need to access both my accounts.
Any advice?
People who have had this problem before have found that they’re accidentally registering for a new account instead of logging into their existing one.
Go slowly and make sure you’re doing the above.
Failing that, what you’ve described is a little too vague so if you would like some help from the community you’ll need to give us some more details.
Explain step-by-step what you’re doing (screenshots help) and the exact error you’re getting 
You could call the number on your card, or email help@monzo.com