Two weeks after the short-term rental tax was signed into law by Gov. Charlie Baker, elected officials and town hall administrators on the Vineyard were busy sorting through the details and fielding phone calls from confused homeowners.

The law, which extends the hotel rooms tax by adding 5.7 per cent to short-term rentals, is already causing ripples on the Island where the lucrative summer rental business is just gearing up for the season.

“As I’m sure is the case for you, my phone has been ringing off the hook,” Martha’s Vineyard Commission executive director Adam Turner told the Edgartown selectmen at their meeting Monday. “People just don’t know what is going on.”

The new law takes effect July 1. It will impose a 5.7 per cent state tax on rentals of 31 days or less. It also contains a provision that allows towns to charge an additional local occupancy tax of up to 6 per cent.

The state Department of Revenue (DOR) has posted a list of frequently-asked-questions (FAQ) on its website about the new law.

Speaking to the Edgartown selectmen Monday, Mr. Turner explained that the 5.7 per cent tax will go to the state while the local occupancy tax will come back to the towns. If Edgartown voters choose not to adopt an additional local occupancy tax at their town meeting this year, he said the tax will automatically be set at four per cent to match the four per cent optional rooms tax previously adopted by the town that currently applies only to hotels, inns and motels.

Selectman Arthur Smadbeck expressed surprise.

“I assumed you had a choice in enacting this, meaning that you would go to town meeting and say we’re going to tax at four per cent,” Mr. Smadbeck said.

“No,” Mr. Turner replied. “Because you are [already] collecting four per cent for your hotels you have to tax at four per cent,” he said. “If you do nothing it would go to four per cent. If you want to do anything else, you have to bring it up at town meeting.”

Mr. Smadbeck expressed confusion about the exemption in the law for landlords who rent for 14 days or less. He wondered whether people who rent out properties for two-week periods throughout the summer would be exempt.

A spokesman for the state DOR clarified later that the exemption only applies to properties that are rented out for two weeks or less. Once a rental exceeds the two-week period, the tax goes into effect for the entire rental period, including the first 14 days, the spokesman said.

Mr. Smadbeck questioned whether the law will result in extra work for the town in terms of tax collection, but Mr. Turner said the state will be responsible for collecting the local occupancy tax and returning the money to the town. In a rough estimate using data from the recent housing production plan, he said a 4 per cent tax could bring in more than $2 million for Edgartown alone.

“This is a pretty big issue for the town in terms of the revenue coming in,” selectman Michael Donaroma said.

In West Tisbury, town administrator Jennifer Rand said the phone calls have quieted down since a link to the DOR website was posted on the town website.

But before that, “it was fairly relentless,” Ms. Rand said. “The first couple days [after the law was signed] we had many, many phone calls from homeowners and realtors.”

West Tisbury is the only Island town that has not adopted the optional rooms tax on hotels and inns. So unless the town votes to change that, town rental properties will only be subject to the 5.7 per cent state tax, Ms. Rand said. “People really want to know what we’re going to do because they’re trying to solidify their rentals now,” she added.

Selectmen plan to discuss the new law at their meeting on Jan. 16, Ms. Rand said.

In Chilmark, selectmen briefly discussed the new law Tuesday night.

“There is state tax legislation that is rather confusing if you have read it all,” selectman James Malkin said. “There are a number of questions I have . . . particularly how it applies to this town, who’s going to collect, who’s going to pay, who’s going to declare, and if we as a town need to take action at an annual town meeting. My view on this is that at this point we should wait . . . but I need more information on how exactly this is going to work.”

Like Edgartown, Chilmark has previously adopted a four per cent rooms tax.

Joan Malkin, who represents the town on the Martha’s Vineyard Commission, spoke briefly about another provision in the law that allows some towns to tack on another 2.75 per cent to create a Cape and Islands Water Protection Fund. Mrs. Malkin said only Edgartown, Oak Bluffs and Vineyard Haven among the six Island towns will have the option of adding this tax and only if they present a comprehensive wastewater treatment plan.

“The three down-Island towns can elect to impose an additional 2.75 per cent; this town cannot,” she said.

The bill also includes an optional, additional three per cent community impact tax that could be imposed on people who rent two or more professionally managed short-term rentals in the same town.

With so many questions remaining, Mr. Turner told the Edgartown selectmen:

“I don’t understand all the impacts either. Give me a month or six weeks and I’ll come back with more information.”

Noah Asimow, Landry Harlan and Holly Pretsky contributed reporting.