He is widely acknowledged as one of Britain's most versatile voice actors. In 2001, he did commercials for Zed Credit Cards in New Zealand as one of his characters, Brains, from the cult television series Thunderbirds (1965). The
company's tagline is "Zed - the card with Brains".
[on Parker in Thunderbirds Are Go (2015)] He's in my vocal DNA, so I didn't really have a lot of trouble regenerating him. I'm getting on a bit, but my voice hasn't changed that much.