(You can read more about how to complete the new form W-4 here. Freelancers and independent contractors not subject to withholding can read about their revised forms here.)

The more allowances you claim, the less federal income tax your employer will withhold from your paycheck, which means the bigger your take-home pay. The fewer allowances you claim, the more federal income tax your employer will withhold from your paycheck and the smaller your take-home pay. If you don’t have enough withholding, you’ll owe Uncle Sam at tax time. If you have too much withholding, you’ll be due a refund. The key is to find the right balance.

(To see whether you’re withholding the right amount, consider checking out the new IRS withholding calculator. You can find more here.)

You may need to file and pay taxes even if you’re paid under the table. We’ve all heard the term “paid under the table”—that typically means that the employer is paying you off the books. If that’s the case, your employer may not be reporting wages paid to you to the tax authorities. That can be a big mistake on the employer’s part and can cost them money in penalties, fines, and unpaid taxes. But Luscombe says not to let their mistake become your mistake: If cash that is paid to you for work that you’ve done is considered taxable income, you’ll need to report it even if the employer doesn’t issue you any tax forms. No matter what your employer does, you’ll want to do the right thing.

Don’t forget about state and local taxes. The focus on federal income taxes tends to be so overwhelming that kids (and their parents) forget about state and local taxes. Unlike federal returns which exempt some low-income workers from filing returns, some state and local tax authorities impose taxes on the first dollar of income. Additionally, some states offer tax credits or other forgiveness for low-income taxpayers, but you have to file in order to qualify. Luscombe says to make sure that you don’t overlook filing and payment requirements for state and local taxes.

You may be able to claim job-related expenses. If you have a “regular” job—meaning one where the employer issues you a form W-2—you can no longer claim unreimbursed job expenses on your federal income tax return as the result of tax reform. But kids who work for themselves, whether from mowing lawns, selling lemonade or some other entrepreneurial venture, can still claim job-related expenses on a Schedule C. Those expenses need to be related to your trade or business and considered “ordinary and necessary.” Keep receipts: Luscombe says the best practice is to keep contemporaneous records to produce at tax time.

(You can read more about Schedule C expenses here.)

Consider using a tax professional. It’s likely not necessary to run out and hire a tax professional to cover your McDonald’s paycheck, but if you have a more complicated tax return, it might be beneficial to use your parents’ tax preparer in 2018. The rules for reporting earned income—meaning wages from your job—haven’t changed as a result of tax reform, but the kiddie tax rules got a makeover. It used to be the case that kids could report unearned income on their parents’ tax return since the kiddie tax rates were the equivalent of the parents’ tax rates. But, Luscombe notes, that changed with tax reform. Now, he says, for federal income tax purposes, the kiddie tax rates are the same as trust tax rates. And even though a draft “postcard-size” tax return has been released (you can see it here), Luscombe says that we’re still not sure how all of the details will work—including the options for children to report unearned income. There may also be specific situations, like teens or college students who are married, that complicate matters just a bit more. The solution might be to let the pros sort it out.

(You can see the 2018 tax rates here.)

Save for a rainy day. So what’s a kid to do with his or her hard-earned money? After you’ve spent a dollar or two on necessities (yes, I’m aware that both Ant-Man and Jurassic World are currently playing), consider saving the rest. And you don’t have to do the expected. Rather than stashing your cash in a typical savings account, Luscombe suggests that you consider a Roth IRA. With a Roth IRA, you pay taxes on your contribution but the income grows tax-free for federal income tax purposes, and qualified withdrawals are also tax-free for federal income tax purposes. A child can contribute up to the statutory limit ($5,500 in 2018), or his or her earned income, whichever is less. And one more thing: A Roth IRA for your child doesn’t have to be funded using only your kid’s income. As the parent, if you want to kick in a few dollars to maximize the contribution, that’s okay, too (see Ashlea Ebeling’s take on that here).