By Andy Metzger

BOSTON -- Hoping to cash in on the new federal tax law, some Bay State workers have shown a growing interest in forming limited liability companies in time for the tax year that starts Monday, but a top state official is urging them to look before they LLC.

The "key advantage" for small business owners under the new law passed by congressional Republicans is a provision enabling them to reduce the taxable portion of their "pass through" income by 20 percent, said David Johnson, the Massachusetts and Rhode Island chapter president of the National Association of Tax Professionals.

That advantage might make it more lucrative for ride-hailing service drivers, hairdressers and artisans who previously did business on their own to register as an LLC. But Secretary of State William Galvin said there is some uncertainty about what lines of work will be eligible for the tax break.

"If you're going to create it for the purpose of taxes you might want to do it this week, but there's no certainty of it. That's why I say we strongly recommend that people consult with their individual tax adviser before they make a strategic move," Galvin said. "But some people have concluded that it will help. We've had an increase in interest in forming LLCs."

An opponent of the tax overhaul signed by President Donald Trump last week, Galvin acknowledged that it offers savings for entities that "pass through" income to the owner, such as LLCs, although he said there are some unanswered questions about what particular businesses can take advantage of that.