The IRS letter confirming your stimulus check isn’t junk mail. You’ll want to keep it.
Angela Lang/CNET

As of last week, the IRS had sent approximately 163 million third stimulus checks to eligible people. The agency mails a letter signed by President Joe Biden after sending each check to confirm your payment. But if you didn’t get your check — or you think it’s the wrong amount (check with our stimulus check calculator) — hold on to the IRS notice to claim what you’re supposed to get under the American Rescue Plan Act.

If the IRS calculated your total based on 2019 taxes but you made less money in 2020, you may be owed more than you actually got. You may have also gained a dependent, like a new baby, that the IRS didn’t use to calculate your amount. And if you moved recently, make sure you let the USPS and IRS know so the document arrives at your correct address.

If you’re part of the millions of people who didn’t get a first or second stimulus payment you were eligible for, you’ll need to claim it as a Recovery Rebate Credit when you file your 2020 tax return — which is due May 17. (You can use our first stimulus check calculator and second payment calculator to help find your estimated total.) If you never received the IRS letter or you misplaced it, we can tell you how to get a copy so you can claim your missing stimulus money from the third check so you can trigger an IRS payment trace. By the way, here’s what to know about a fourth stimulus check.

What the IRS letter (Notice 1444) is, and why you should keep it

The IRS is now sending out a letter following your third stimulus check, confirming your payment. Officially called Notice 1444-C, the letter signed by Biden shows you the amount you were paid and how you were paid — by mail or direct deposit. The letter also advises you to check the Get My Payment tool or call a phone number at the bottom of the letter if you’ve not received your check.

With the two first stimulus payments, the IRS also sent a confirmation letter in the mail within 15 days of your payment going out — Notices 1444-A and 1444-B.

If you believe you received the wrong amount — such as a dependent was skipped — or the total doesn’t match the estimated amount from our stimulus calculator, it could indicate that you may need to hunt down your missing money using this letter. The IRS advises you to hold on to the letter for your 2021 tax records.

What this really means is that it’s useful if you need to claim missing money in the future, as you can now on your 2020 taxes as a recovery rebate credit for the first two checks.

Here’s more information on using the Recovery Rebate Credit Worksheet to figure out the credit from the first two checks that you can claim on your 2020 taxes. You’ll essentially enter the total amount you determine you’re owed on line 30 of the 2020 1040 or 1040-SR tax forms.

What if I now have a new address?

The IRS would have mailed a notice to your last known address with your information on the payment. You’ll need to inform the IRS and USPS if you’ve moved. The IRS needs to independently have your correct information on file.

Where can I locate the IRS information if I can’t find the physical letter?

If you don’t have the IRS confirmation notice, you should be able to find the information in your federal tax account, using the IRS website.

If you don’t have an account set up with the IRS, head to the IRS account page and tap the blue button that says Create or view your account to get started.

You’ll need to have some information on hand to set up your account, including tax and financial information, plus an email address and a mobile phone number to receive activation codes.

The IRS said for married couples who are filing jointly, each spouse will need to log in to their own account.

The IRS has sent out two rounds of stimulus payments.
Sarah Tew/CNET

What can I do if I can’t complete the IRS registration?

The online registration process can take about 15 minutes. During the setup process, the IRS will first email and then text two activation codes. If the codes don’t come through, the agency will mail you a letter with an activation code, which can take five to 10 days to get to you. If you want to track the letter, you can use this free service from the USPS.

Once you’ve set up your online account with the IRS, you can check your account for the information contained in the notice. If your stimulus payment information is not available when you check, the IRS said it should be in the coming weeks.

Here’s more information on tax season and your stimulus check, everything you need to know about the third stimulus check and what could happen with a fourth stimulus check. Here’s what we know about payments for the Child Tax Credit.