Close to 100,000 homeowners rushed to register for the property tax over the Bank Holiday weekend as the first deadline hit.
Over 500,000 houses are now registered for the tax as the Revenue Commissioners' campaign kicks in.
The last-minute surge in registrations means just short of one in three homes are now signed up for payment.
The deadline for registration by post passed yesterday, but the Revenue will accept forms today that have yesterday's postmark.
Revenue said the number of registrations over the Bank Holiday was "close to 100,000, on top of the 400,000 already".
"The 100,000 includes post, online and online returns completed via the LPT (Local Property Tax) helpline," a spokesperson said.
And this figure is expected to rise further today as the remainder of the weekend post arrives. Anyone who didn't register yet has another three weeks to do so via the website or the LPT helpline number of 1890 200 255.
The deadline to register online is May 28, and the tax will be collected from July 1.
