We're in the middle of tax season, but plenty of families are still uncertain what the new tax law will mean for them.

Indeed, nearly half of the families polled in a study by Haven Life said that they had no clue how the Tax Cuts and Jobs Act — the tax overhaul that took effect last year — would affect their 2018 taxes.

Haven Life surveyed 550 consumers with kids under age 17 from January 31 to February 4.

"There are a lot of moving pieces," said Cathy Derus, a CPA at Brightwater Accounting, of the new laws.

Here's what families need to know about the tax law this filing season.

Tax law changes for families

Key changes from the new tax law include a higher standard deduction — $12,000 for singles and $24,000 for married couples filing jointly — as well as the loss of personal exemptions and limitations on itemized deductions.

Families with kids under age 17 should be aware that the child tax credit has also doubled to $2,000 per qualifying child.

This credit is refundable up to $1,400 — meaning that if the credit is greater than the tax you owe, you'll get a refund for the difference.

Further, working parents with kids under age 13 still have access to the child and dependent care tax credit. This tax break offsets the cost of daycare, summer camp and sitters.

It maxes out at $1,050 for one kid under 13 or $2,100 for two or more kids under 13.

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Finally, the new tax law has expanded the use of 529 college savings plans, accounts that accumulate free of taxes and that may be tapped tax-free for qualified higher education expenses.

Under the Tax Cuts and Jobs Act, families can now tap their 529 plans to cover private elementary and secondary school tuition and do so free of taxes.

Be aware that not all states will permit families to do this — and some will claw back state-level tax benefits if savers tap their plans for K-12 costs.

What should you do with your refund?

Six out of 10 respondents indicated that they would use their tax refund money to pay down their debts, according to Haven Life's study.

"I don't like that so many people have so much debt, but I like that they are being responsible," said Derus.

About a third of participants said they would save their money in a basic savings account, while nearly 3 out of 10 said they would spend it on something fun.

There's no reason you can't split your refund to meet all three goals, said Derus.

"Pay down some debt, and save some money for the future," she said. "But also if you get this money spend some of it for fun."

What if you owe taxes?

If you wind up owing the IRS this tax season, consider double-checking your tax withholding at work, said Derus. This way you can avoid owing next year.

After the Tax Cuts and Jobs Act, Treasury and the IRS updated the tax withholding tables, which your employer uses as a guideline to determine how much income tax is withheld from your pay.

Your Form W-4, which you can update at any time, allows you tailor your tax withholding at work.

If you withhold too much in taxes, you'll get large refund next year, but your paycheck will be smaller.

Withhold less and you'll get more money in your paycheck now, but you'll end up with a smaller refund next spring. If you withhold too little, you might owe the IRS.

Another way to curb your tax bill next year is to consider raising your 401(k) plan contribution, Derus said. Your deferrals at work reduce the amount of your wages that are subject to federal income tax.

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