Two-thirds of U.S. taxpayers are worried about not getting their tax refunds on time, according to a new survey.

Among the 1,000 people who responded to the online survey, 36.9 percent were "very worried" that they will not receive their refunds on time and 30.3 percent were a "little worried," according to Salary Finance, a provider of salary-linked loans for employees that commissioned the survey.

"The shutdown and potential delay in tax refunds comes at a time when most Americans are not in a position to take on additional financial stress," Salary Finance CEO and co-founder Asesh Sarkar said in a prepared statement. "According to the U.S. Federal Reserve, 40 percent of American adults can't afford a $400 emergency expense."

The survey found that a delayed tax refund could push more than one in five people to take on additional debt and cause nearly one in 10 to overdraft checking accounts, the company said.

About 40 percent of respondents said that they plan to use their tax return to pay off debt and loans, and 16 percent earmark their tax return to pay off medical debt, the company said. "Another 32.6 percent said that they rely on tax returns to stabilize their bank accounts."

The survey also found that 43 percent of respondents say they will struggle to pay their day-to-day bills, and 12.1 percent will rely on family and friends to help them with bills.

The survey "highlights how daily financial challenges will increase for many Americans who depend on their annual refund to catch up on bills," Sarkar said. "The road to financial wellness will get much harder for many households nationwide if tax refunds are delayed."

The survey was conducted this month by SHIFT Communications, the company said.