"I only ever cross borders with a blank phone because I don’t want you invading my privacy" is a perfectly valid answer. You can also add that it is your employer’s policy and/or your government official recommendation.
Makes no difference at all in the real world. You don't have to give valid answers, you need to get the guy across from you to not find you suspicious. That phrase is going to put a red flag on you, valid or not.
> you need to get the guy across from you to not find you suspicious.
What? No, who cares about that? Let him find you suspicious, what matters is that he doesn’t access your data. And it is not suspicious to cross borders (esp. US borders) with burner phones. As others have said, it is standard practice.
He doesn't access your data. He confiscates your phone, then still doesn't access your data, then denies you entry, then still doesn't access your data, then holds you in immigration detention for a week while he tries to access your data, which he can't. Is that a success? Maybe, if your data really is that valuable and a successful border crossing isn't.
> Maybe, if your data really is that valuable and a successful border crossing isn't.
Even if my data consisted entirely of cat pictures, it would be more valuable than successfuly crossing the border into a country that actively tries to invade my privacy.
To cross said border with my burner phone in my pocket and do whatever I need to do on the other side, why else? You do realise that is by far the most likely outcome, yes?
I have worked for employers that required taking a burner phone to certain countries without any accounts logged in, etc. (so mostly for calls, maps, and web browsing) and nobody has ever been detained or denied entry. Some countries know that this is just standard procedure when they are visited for business trips. Probably different for the US though.
(Not legal advise of course, just observation. Always check with the legal department of your employer, etc.)
Lying about what? "I only bring a burner phone to border checks because I don’t want people like you to access my data“ is not a lie, and I fail to see how it could be interpreted as such.
"I have to do this because of country X, you know that they're like, amirite?"