The Internal Revenue Service and U.S. Treasury certainly have done a remarkable job of disbursing one hundred fifty-six million coronavirus stimulus checks worth $372 billion in the middle of a hectic tax season.

However, amid the mad rush to fast-track the stimulus money out to cash-starved Americans, there has been a steady stream of reports indicating that some payments may need to be returned to the IRS.

The first group of people that should send the money back are those who fit into the category of nonresident aliens. According to the agency, they are not eligible for the third stimulus checks. In most cases, they are not a U.S. citizen, don’t possess a green card, and often are not physically present in the United States for the required amount of time.

However, a lawful permanent resident with a valid Social Security number who pays taxes in the United States is entitled to the stimulus check. These particular residents are individuals who are legally residing permanently in the country as an immigrant, and they are generally given an alien registration card, also known as a green card.

Keep in mind that it is possible, though, to be a qualifying resident alien without having a green card. The IRS says that this includes people who are physically present in the United States on at least thirty-one days during the current year, one hundred eighty-three days in the past three years, including the current year, and possess a valid Social Security number. They also cannot be claimed as a dependent by another taxpaying individual.

Even as a non-U.S. citizen, know that there are still income thresholds that one must meet in order to qualify for the direct payments. Individuals who earn as much as $75,000 in adjusted gross income (AGI), or couples making $150,000—in addition to their children or adult dependents—qualify for the full $1,400 per individual. Moreover, single parents with at least one dependent who earn $112,500 or less also get the full amount.

The second group includes taxpayers eligible for stimulus payments who died before January 1, 2021, but were still sent checks—and the IRS has given notice that spouses or relatives will need to return the funds to the agency. Know that the extra $1,400 per dependent is also not available for a parent who died before that date.

However, there is one exception: If the person who died is a married member of the U.S. military, the surviving spouse is still eligible for the stimulus payment.

Finally, there are some people who want to voluntarily return the stimulus payments for whatever personal reason. These recipients should write “void” in the endorsement section on the back of the check and then mail it to a local IRS location. If one decides on this route, they should also write a brief explanation stating the reason for returning the check.

If the payment was already direct deposited into a bank account, then one can send off a personal check or money order to a local IRS location. Just make it payable to “U.S. Treasury” and write “Third EIP” and personal taxpayer identification number (social security number or individual taxpayer identification number) on the check. A brief explanation stating the reason will also be needed.

Ethen Kim Lieser is a Minneapolis-based Science and Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek, and Arirang TV. Follow or contact him on LinkedIn.