She is known for many roles including the voice of Perfect Peter in Horrid Henry, Harry in Harry and His Bucket Full of Dinosaurs, Raggles and Bluebird in Everything's Rosie, Katsuma and Luvli in Moshi Monsters: The Movie, Kipper in The Magic Key and Gran in Kazoops.
Tate debuted in a 1991 episode of The Bill and from 1999, she commenced work in voice acting, mainly in children's programmes, starting with the U.S. version of Bob the Builder and also on Dream Street, voicing Half-Pint the milk float.
In 2006, Emma began to voice Perfect Peter in the TV adaptation of Francesca Simon's book Horrid Henry.
In 2010, she began to appear with Horrid Henry co-star Joanna Ruiz in Everything's Rosie, voicing the main characters.
In the 2013 video game Broken Sword 5: The Serpent's Curse, she voices the female lead Nicole Collard and other minor roles.