Less than a week after President Donald Trump’s tax plan was signed into law, town halls across Massachusetts and in Dartmouth are feeling the effects in the form of residents scrambling to pay their property taxes early.

Although bills are not due until February and May, Town Collector Deborah Piva is expecting long lines and a hectic day on Friday, the last day Town Hall will be open before the new year, as more residents than usual are paying their property taxes months in advance to maximize their tax deductions.

Starting in 2018, Trump's tax plan includes a $10,000 cap on state and local taxes that can be used as a deduction on federal returns. There was previously no cap. That has left many homeowners attempting to pay their bills by the end of the year before the changes take effect to include the payments as a deduction on their 2017 federal taxes.

It's caused one of the busiest end-of-year collection seasons in Piva's thirty-plus years in town. When her office opened on December 28, phones were ringing nonstop and lines were already forming at the collection window.

She’s even heard from an out-of-state property owner who plans to drive from New York state to Dartmouth to pay in person.

“Every year there’s a few people, but this year it’s unbelievable the amount trying to pay for two quarters,” Piva said.

Dartmouth, and cities and towns throughout the country, have been dealing with confusion and uncertainty amid the passage of the law. Piva said her office had received last-minute clarification on a crucial question early this morning: how far in advance residents can pay.

The answer: residents can only pay property taxes that have already been billed. In Dartmouth, that means residents can only pay up the third and fourth quarter real estate and personal property taxes that were mailed out on December 26 and are due in February and May 2018.

For those who cannot make it to Town Hall in time - it closes early at 12 p.m. on December 29 for the New Year's holiday - there are still options. They can be paid online, but fees may apply depending on the payment option chosen.

Third quarter payments can be made online as of December 30 by credit card or e-check through the town's Invoice Cloud service, or by phone by calling (855) 985-1126. Payments made online or by phone by 11:59 p.m. January 1, 2018 will be recorded as received in 2017. Fourth quarter payments cannot be made online or by phone.

Piva said the best option is to place payments in the drop box in the front Town Hall parking lot. Payments placed in the box over the holiday weekend will be recorded as being received in 2017. They must be placed in the box before it is emptied when Town Hall reopens on January 2 at 8:30 a.m.

Checks sent by mail will not be eligible for recording in 2017 because they are recorded based on the date they are received, not the date postmarked.

Town offices are not as busy as in other communities in the state, although Finance Director Greg Barnes noted many residents with summer homes in Dartmouth are among the ones calling in and paying early.

“Around here the it’s a little better because the tax burden is not the same as in the Boston area,” Barnes said.