Almost 20,000 people have received the wrong information on their polling cards following a printing blunder.
A total 19,000 people in Ashford borough were sent the cards for the June European and Kent County Council elections.
Ashford Borough Council explained that information on voting normally for postal electors was mistakenly printed on the backs of those meant for people using polling stations.
The authority says this was due to a system error during the print run involving printers Electoral Reform Services (ERS).
Trevor Robertson, council head of democratic services, said: "We learned of the error the day after the cards were sent out.
"ERS has accepted full responsibility for the mistake and immediately sent out replacement cards and an apology."
Mr Robertson said this was the first time such an error had occurred in ERS and praised its swift response.