Another common question I get when I divulge my job as a voice actor is whether or not I can do any accents or impressions. I'm admittedly not a very good impressionist (there are a few I can do, but that's not really my specialty). But, um, yeah I can do some accents. So that inevitably leads to them wanting a demonstration of this or that accent. It's a trick I've pulled out since I was a wee little kid, and I imagine I'm not the only voice actor who has a history of doing this. Plenty of us have trained to do accents, and can even do some to a degree which passes for authentic. This certainly has come in handy for jobs, which leads me to today's discussion—casting for an accent.
Below is a video of different Hollywood actors being assessed on their ability to accurately portray accents, just as examples of how well and not-so-well actors can pull off accents other than their own. (Warning for some NSFW language.)
I've had many jobs where I was cast as a different nationality, or was to use an accent from a region of the United States (where I'm from) in which I've never lived. But there have been just as many castings which specify wanting ONLY talent from that country/region, because they want the accent to be authentic. So, let's talk about some benefits for both options—casting folks either native or foreign to the desired accent.
Ideally, of course, you'd want the accent to always be as accurate as possible (unless there's a reason for it not to be). That is, without a doubt, the largest benefit to casting someone who is a native speaker with that accent. The only thing which may make this option difficult is finding someone who fits that criteria. Which is why someone may just be interested in the best impression of that accent they can find. I know I've said this before, but honestly that's one of the great things about FlyVoiceovers, that it has a roster from around the world. That makes it insanely easy to find someone who just naturally has that accent.
But, hey, maybe you've worked with a certain talent before and you like their acting style and know they can pull off whatever accent you throw at them. This is a potential benefit for hiring someone not native to the desired accent—they are a known factor, and you don't have to risk going with someone new and untested (it's why those Hollywood actors in the video were cast, after all). Plus, who knows, maybe all the native speakers you found just don't have the right voice, but this person does. Or maybe you need them to speak in one language but have the accent of another (like you need them to sound like an Australian speaking Japanese), and you just can't find someone with the fluency to adequately pull it off, so have to go with someone native to the language and not the accent.
Maybe it's just an incidental thing, like you're casting for an audiobook which is primarily British but a few characters are from Korea or Nigeria. Or maybe it's an e-learning course, and there's a fun little scene to test what they've learned, which includes a zany cast of characters from different backgrounds. You aren't going to cast different actors for those tiny bits while all the rest is a single actor (I mean, you could, but that's not very likely).
There can be potential pros and cons to hiring either a native speaker with that accent or someone doing an impression of it. Ultimately it boils down to what you need and what talent you're able to have access to. It also doesn't hurt to ask a talent—or a talent's agent—which accents are in their repertoires and if they'd be willing to do a little sample to see if it passes muster. Because, again, it might just be a little thing you need, and while you've already got them booked for a character in a game or some lines for a commercial, you might as well just see if they can record this other small bit, too. Save you the hassle of having to go back out there searching for new talent. But if it's for a project where that's the primary accent needed, and you absolutely have to have it be authentic, then something like FlyVoiceovers would be able to help you find exactly what you need.