The elections, for the North East Mayoral Combined Authority and Police and Crime Commissioner for Northumbria, take place on May 2.
The Council has requested that completed ballot packs are sent back as soon as possible, ideally being posted directly into a Royal Mail box.
Any undecided postal voters are urged to get their votes in, as those received after 10pm on May 2 will not be counted.
If postal voters miss their deadline, they can hand their postal votes in at their polling station or at County Hall, Morpeth.
Current rules allow for individuals to hand in only their own postal vote and those of up to five others, but a postal vote return form must be completed.
This includes the voters name and address, and the number of postal votes that are being handed in and the reason why they are handing in those postal votes.
Political campaigners can only hand in their own postal vote, and postal votes for up to five other people that are either close relatives or someone they provide regular care for.