By now, millions of Americans have received their third stimulus check, but some of the recipients of the $1,400 direct payment need to return theirs to the government.

According to Kiplinger, there are a few reasons a person might need to send the check back to the IRS. The first is if the recipient is classified as a nonresident alien. This means they are not a US citizen, do not have a green card, and aren't in America for a required amount of time. While qualifying resident aliens who have a green card and a Social Security number were eligible and can keep their check, the nonresident aliens might have gotten one by mistake and need to return it.

Others who have to send their check back are some widows and widowers. If a married couple received the payment but one of the spouses has passed away, it needs to be returned along with a letter explaining the situation. At that point, the IRS will re-issue a payment just for the living spouse.

There is also a third group of people who are supposed to send their checks back, but are not required to. It's anyone who doesn't need or want the money. The IRS is encouraging them to return their payments.

If you fall into any of the three groups, and received a debit card, you can mail it back to: Money Network Cardholder Services, 2900 Westside Parkway, Alpharetta, GA 30004. Be sure to include a note as to why you don't want it. As for the paper check, you'll have to void it by writing "void" in the endorsement field, then send it back to the appropriate IRS address below with a note that includes the reason you are returning it. If you've already deposited the check or it was a direct-deposit, make a personal check out to US Treasury and write Third EIP and your taxpayer ID number in the memo field. Once again, include an explanation of why you are returning it and send it to the appropriate address below.

There is no word on what might happen if you don't send a check back that should be returned, but knowing the IRS, they will likely find out about it and eventually it will catch up to you.

If you live in Maine, Maryland, Massachusetts, New Hampshire, Vermont:

Mail to:

Andover Internal Revenue Service

310 Lowell St.

Andover, MA 01810

If you live in Georgia, Iowa, Kansas, Kentucky, Virginia:

Mail to:

Atlanta Internal Revenue Service

4800 Buford Hwy

Chamblee, GA 30341

If you live in Florida, Louisiana, Mississippi, Oklahoma, Texas:

Mail to:

Austin Internal Revenue Service

3651 S Interregional Hwy 35

Austin, TX 78741

If you live in New York:

Mail to:

Brookhaven Internal Revenue Service

1040 Waverly Ave.

Holtsville, NY 11742

If you live in Alaska, Arizona, California, Colorado, Hawaii, Nevada, New Mexico, Oregon, Utah, Washington, Wisconsin, Wyoming:

Mail to:

Fresno Internal Revenue Service

5045 E Butler Avenue

Fresno, CA 93888

If you live in Arkansas, Connecticut, Delaware, Indiana, Michigan, Minnesota, Missouri, Montana, Nebraska, New Jersey, Ohio, West Virginia:

Mail to:

Kansas City Internal Revenue Service

333 W Pershing Rd.

Kansas City, MO 64108

If you live in Alabama, North Carolina, North Dakota, South Carolina, South Dakota, Tennessee:

Mail to:

Memphis Internal Revenue Service

5333 Getwell Rd.

Memphis, TN 38118

If you live in District of Columbia, Idaho, Illinois, Pennsylvania, Rhode Island:

Mail to:

Philadelphia Internal Revenue Service

2970 Market St.

Philadelphia, PA 19104

If you live in a foreign country, U.S. possession or territory, or use an APO or FPO address, or file Form 2555 or 4563, or are a dual-status alien

Mail to:

Austin Internal Revenue Service

3651 S Interregional Hwy 35

Austin, TX 78741

Photo: Getty Images

Steph