Grammy award-winning Sheeran, songwriter and producer of I See Fire, commissioned for The Hobbit: The Desolation of Smaug, appears to have followed in Sir Peter Jackson's footsteps.
Mcfarlane said about five years ago Sir Peter was tattooed by shop owner Greg Burt.
Mr Mcfarlane said efforts were made to keep the singer's visit to the shop a secret.
"I met [Sheeran] ... last Monday evening and organised a tattoo for Wednesday.
"It was just a matter of trying to get him in the shop without people finding out.''
Mr Mcfarlane would not divulge what the tattoo was of, saying tattoos were "private and personal''.
"He was really stoked ... he couldn't thank me enough.''