Businesses in St. Lawrence County can get help with the state’s new online sales tax filing system as the telephone help line hours are extended.

The state Department of Taxation and Finance launched an improved and more user-friendly system in September, but for nearly 250,000 users around the state, December will be their first time using the new system to file returns.

The filing deadline is Dec. 20.

In order to assist businesses and tax professionals in St. Lawrence County and across the state as they file sales tax returns with the new system, the help center’s hours through Dec. 20 will be 8:30 a.m. to 7 p.m. weekdays and 9 a.m. to 1 p.m. on Saturday, Dec. 15.

The call center’s phone number is (518) 485-2889.

The new technology allows businesses to perform all sales tax filing and reporting tasks online and reflects requests and input from thousands of users from New York’s business and tax professional communities.

The enhancements are intended to help businesses comply with their sales tax responsibilities while enabling the department to make more accurate distributions of sales tax revenue to local governments.

The department’s web site also offers online demonstrations of the new system at http://www.tax.ny.gov/e-services/otc/demos/demo.htm.

Users also can sign up for free webinars to better understand how to use the new services. They are scheduled for 10 a.m. Dec. 14 and 1 p.m. Dec. 18.

Businesses can register for the webinars online at http://www.tax.ny.gov/bus/st/stmp.htm.

There will be additional webinars in the new year.