Paul Jefferies has been the credited sound effects editor on the BBC Wales version Doctor Who for nearly every episode since Rose. He has had a particularly long working relationship with dubbing mixer, Tim Ricketts, with whom he has won five Welsh BAFTAs since 1994. Their work on Midnight earned them not only a Welsh BAFTA, but a prestigious Royal Television Society Award. He has also worked with Ricketts on Toby Whithouse's Being Human.
He was a documentary subject on Doctor Who Confidential in the episodes that accompanied Father's Day, Midnight, and The Hungry Earth.