More than 15,000 reminders are being sent out to residents who have not yet responded to a letter inviting them to register to vote.
Electors are encouraged to respond straight away, otherwise they may receive a house visit and more leaflets encouraging them to respond.
Those who have received an invitation to register can respond via an online application.
Alternatively, they can also complete and return a printed household inquiry form.
It will need to be completed and returned – the postage of which is pre-paid.
Documentation will then be sent to each person named inviting them to register individually.
Abdool Kara, Swale council’s chief executive and electoral registration officer, said: “The response has been a lot lower than we would have hoped for.
“Having said that, this trend has been seen across other areas of Kent so is not unique to Swale.
“There are a number of reasons to register to vote, not only does it mean that you will be able to vote in future elections and referenda, but it may also help you if you wish to apply for credit as credit reference agencies will refer to the electoral register.”
To view the online registration system visit www.gov.uk/register-to-vote