The Non-Principal Private Residence payment was brought in five years ago to target landords and holiday home owners - but it's now been replaced by the general property tax.
Anyone who misses this Sunday nights deadline will have to fork up to seven thousand Euro, which is almost double the original charge.
But if anyone contacts Donegal County Council, admitting they're in financial hardship and currently cannot pay the charge, then they will not be penalised.
Paul McSweeney from the Local Government Management Agency, said if people can get in contact before Sunday, then payment arrangements can then be made:
Anyone who is in genuine financial difficulty and still have not paid the NPPR tax can contact Donegal County Council by post, or email or by telephone by midnight on Sunday.
Any queries relating to the NPPR charge in Donegal can be emailed to email@example.com