Households have until midnight tonight to register their details with Irish Water or they may face a default charge of 260 euro.
So far, over 1 million people have returned forms and will be eligible to apply for the 100 euro Water Conservation Grant.
Another wave of national protests against the water charge took place this weekend, to coincide with the registration deadline at midnight tonight.
Irish Water says over 1 million people have returned their application packs, leaving over 835-thousand yet to register.
The utility is urging those who are yet to submit their details to do so so they not only receive the correct bill, but are also eligible to apply for the 100 euro Water Conservation Grant, introduced by the Government in November in light of rising public backlash against the charge.
Any unregistered customers are being warned that they will receive a default bill at the capped charge of 65 euro per quarter, or 260 per year, with the first bills being sent out from April.
