Baby Alexander McConnell was born in February 2009
A 15-month-old baby has been sent a polling card for the general election.
Alexander McConnell, from Southwold in Bicester, Oxfordshire, received the card in the post along with cards for his parents Ian, 38 and Gaynor, 37.
Cherwell District Council said his parents had made a mistake filling in an application form.
Mr McConnell said: "I thought it was a joke at first, then I wondered who else might have got the wrong card."
A spokesman for Cherwell District Council said: "The reason that Alexander was sent a polling card is that his name was entered on the application form despite the form stating that no one under 16 should be listed."
Mr McConnell, a sales manager for Mercedes, and his wife, an administrator, said they had registered their son's birth, but said it was not the case that they had filled in forms incorrectly.
Mr McConnell said: "The three polling cards all turned up and I didn't think anything more of it.
"I didn't realise just how rare this was until I spoke to a friend last night and he mentioned that a six-year-old boy was all over the news on Radio 4 last week."
Mr and Mrs McConnell are intending to vote at their local polling station in Southwold.
They said were intending to keep Alexander's card "for a bit of fun".