Finn has started getting leaflets from council election candidates
Normally you have to wait until you are 18 before you can cast your vote.
But two-year-old Finn Proveniers may have a chance, on paper at least, after he was sent a polling card.
His father Han, an interior designer, said the family chuckled and put the card in a cupboard when it was first sent out a few weeks ago.
But Finn has started getting leaflets from council election candidates in Ammanford, Carmarthenshire asking him to vote for them on 1 May.
"It's surely only a matter of time before we get candidates calling personally asking for Finn's vote - we have been canvassed in previous elections," said Mr Proveniers.
He believes the mistake may have occurred when he filled in a form for the electoral register in Carmarthenshire after moving house 18 months ago.
It asked him to put down everyone who was living in the house, even if they were below the age of 16.
"I put Finn's date of birth down as 19/9/2005 and possibly the computer has just taken the first two digits of the year from this entry.
"So I think they believe Finn is actually 87!"
A council spokesperson said the electoral registration form issued to every household required them to enter the names of all those eligible to vote.
"It states on the form that those aged 16 and over can be entered, along with their date of birth, which in turn is recorded on the register.
"In this case, the name of the young boy was entered with no date of birth, which is an error on behalf of the householder.
"It is generally known in the UK that the voting age is 18 years and over but should anyone have any queries a helpline number is provided on the form."