Residents are reminded to complete a household enquiry form to ensure they are registered to vote at local and national elections.
More than 60,000 forms were sent to households by St Albans City and District Council last month, but 26,000 of them have not yet replied.
This is part of the annual voter registration canvass that keeps the electoral register up to date.
They are being sent reminder notices in the post and if they do not act, they risk not being included on the register and losing their right to vote.
The form lists everyone registered to vote at a particular address. Residents should check that the information is correct and no names are missing or wrongly included.
If no changes are needed, they should confirm this online at www.householdresponse.com/stalbans
Alternatively, they can do so by free phone or text with full details of these included in the form.
If the form needs to be amended, this can be done on the website or by post, using a freepost envelope which is enclosed with the form.
People’s names need to be on the electoral register in order for them to vote at elections within the District.
Michael Lovelady, Electoral Registration Officer for St Albans City and District Council, said: “I’m pleased that so many residents have already responded.
“However, it’s important that those who haven’t done so do this as soon as possible. We want to make sure we have the right details on the electoral register for every address in the District.
“To make sure you are able to have your say at future elections, act now and check the form.”
If you’re not currently registered, your name will not appear on the form and you can register online at gov.uk/register-to-vote
People who have moved address recently are particularly encouraged to keep an eye out for the form and check the details.
Residents who have questions can contact the elections’ team by email at email@example.com or by telephoning 01727 819294.