Upvote:1
I was going to Zimbabwe. We'd heard that non-African countries can sometimes be charged more. So I had both my South African and my New Zealand passports ready. Turns out we were fine and got waved through, but as I went through the agent asked 'wait, and who's passport is THAT one?' pointing to the second passport. 'Oh mine' I answered and just kept walking.
So it was potentially useful, and also potentially problematic.
Also some countries (eg South Africa) require you to enter on your South African passport if you have one. So using the wrong one to enter could be problematic then.
Upvote:4
A few cases where it may be a problem:
Other than that, border officers and airline agents must see the case all the time and will be completely unfazed. I personally never had any issue with that. And in many cases, it's actually either required or very helpful to carry both.
Upvote:7
Question 1: Can it ever be harmful to bring my 2nd passport?
Sure.
my mom threatened to cancel our trip because I really insisted on bringing both passports
I see no grounds for her insistence, but also no need to bring this second passport, do I'd let her have her way.
Apart from this, the only reason I can think of is a specific political situation. E.g. don't take an Israeli passport to Iran.
And then you can always come up with what-ifs. If you take the passport you might lose it. If you don't, your house may be burgled and you're passport stolen. If you do, a policeman may think you're Jason Bourne. If you don't, you might find that immigration rules changed last minute and the second passport would have saved the day. None of this is likely.