Parents, relatives, employers and nonprofits also can contribute to the accounts. Businessman Michael Dell and his wife Susan have pledged to put $250 in each of the accounts of 25 million children who are younger than 10 today.

But some tax experts think lawmakers overlooked a tax requirement that could make the accounts too burdensome for most parents.

A contribution to a child’s Trump Account is a taxable gift, which requires the giver to fill out one of the IRS’s more complicated tax forms, Form 709. The 10-page document takes the average filer or their accountant more than six hours to complete, and the government has only accepted mailed submissions; that changes this coming tax season, when e-filing will become available.

It’s used by fewer than 225,000 households a year, federal data show, and is so obscure that commercial tax software like TurboTax doesn’t include it.

“If you want to apply for the $1,000 because your kid was born within the time period, fine. If your employer wants to make a contribution or you qualify for a contribution from a charitable organization … fine. But don’t put your own money in until this is clarified,” said Susan Bart, a lawyer who specializes in estate and gift tax.

Most gifts aren’t nearly this complicated. Under long-standing law, most people can give cash gifts to one another tax-free. But if it’s a sizable amount – more than $19,000 – the IRS requires the donor to file Form 709. Over time, if those gifts add up to more than $15 million in the giver’s lifetime, they need to pay certain taxes. The whole system is meant to prevent very wealthy people from doling out large cash gifts during their lifetimes so their heirs can avoid estate taxes later.

But because there’s no provision for contributions to Trump Accounts to count as exempt gifts under current tax law, donors would have to declare every contribution, several tax experts say. This applies whether the donation is $25 or as much as the $5,000 annual cap. That’s because to be considered a tax-exempt gift, the recipient has to be able to access the money right away. Trump Account beneficiaries cannot withdraw the money until they turn 18.

Asked whether Trump Account contributions are required to be reported, an IRS spokesman referred questions to the Treasury Department, where several officials did not answer questions from The Washington Post.

The American College of Trust and Estate Counsel, a lawyers group, sent a letter raising the issue to the congressional tax-writing committees last month. The group’s Washington affairs chair Kevin Matz said his group received no answer beyond acknowledgment that the letter was received.

Congress has dealt with a problem like this before. Lawmakers approved a clause exempting 529 accounts – the tax-advantaged savings accounts for a child’s education – from the requirement that the recipient have present use of the gift. That means parents, grandparents and others can put money in 529 accounts without filing gift tax returns.

The experts who raised the issue are calling on Congress to make the same legislative fix for Trump Accounts.

“It seems like legislators accidentally left that out,” Waldman said.

The 10-page tax form asks a series of questions that are nearly indecipherable to the uninitiated. It distinguishes gifts that are “generation-skipping” – such as a grandparent giving money to a grandchild. When a married couple makes a gift, it probes whether the amount can legally be considered split between them, or attributable to just one.

Even experts scratch their heads. “Not all accountants necessarily have the experience and background to be able to complete it without extensive study,” Matz said.

Bart agreed: “It’s not a DIY form by any means.”

She said she’s seen lawyers befuddled by Form 709 before. “Sometimes my partners in other practice areas who are very, very smart people, they think: I can do this for my own kid or grandchild. They come running back after they look at the form a while. You need to be a specialized attorney with a lot of experience in the area.”

Many people might contribute to Trump Accounts without knowing that they are supposed to file Form 709, and aren’t likely to file it. But experts believe that skipping the form could create problems for the parents if they’re ever audited. Or if tax software like TurboTax starts including Trump Account questions, the taxpayer might not be able to submit their returns through the software if they indicate that they gave to the accounts.

Parents can still create Trump Accounts for their children to receive money from the government and charities like Dell’s without triggering the tax form problem.

“Of course if the government’s giving you a free $1,000, go ahead and take it. That’s not going to hurt you,” Waldman said. “If you’re thinking about personally contributing, consider your other options.”

Even without the tax-filing complications, Trump Accounts might not be the best way for most parents to save money for their children, experts say. The 529 plans offer much better tax benefits – unlike Trump Accounts, parents can often take some state tax deductions when they put money into the account, and if the child uses the money to pay for education, the earnings inside the account are never taxed.

If parents want a multipurpose savings vehicle for their kids that is not just limited to education spending, an ordinary taxable brokerage account might also be a better choice, tax professionals say. Trump Accounts are untaxed during the beneficiary’s childhood, when the money is growing in the account, unlike a brokerage account that could require paying taxes on any dividends. But the tax treatment when the child does withdraw the money could be much more favorable on the brokerage account – that money gets the lower capital gains tax rate, while Trump Account withdrawals are taxed at the same rate as ordinary income, and even come with a 10 percent tax penalty if the child doesn’t use the money for a qualified purpose. And the brokerage account offers a much wider range of investment options.

“As a tax-advantaged account, it’s a terrible tax-advantaged account,” said Greg Leierson, senior fellow at New York University’s Tax Law Center.