The stimulus check wheels are once again in motion. The IRS is sending second stimulus checks in the mail and turned on its online stimulus check tracker tool, which will ballpark your payment schedule, let you know your second stimulus check total and tell you if there’s been a holdup or other error processing your check.

But if you’re eligible for a second stimulus payment, didn’t already set up direct deposit with the IRS, and are therefor due for a physical check or an EIP card instead, there’s only one tool that can tell you when your payment has been scanned at the post office, or has already been delivered to your mailbox. Enter a free USPS service that works in tandem with the IRS’ online stimulus check tracker to give you a more precise delivery window for peace of mind.

Although the second stimulus checks are coming more quickly this time around, there’s also a catch: a Jan. 15 cutoff date to receive your check. If you don’t get your payment in the mail shortly after that date, you’ll have to file a claim during tax season to get your money. That’s called a Recovery Rebate Credit, and it could slow down your timeline to get your next check. We’ll walk you through how you can use the USPS service to monitor your stimulus check in the mail. This story recently was updated.

What is Informed Delivery and why do I want it?

Informed Delivery is a free mail-tracking service from the USPS that automatically scans your letters and can alert you with an image each time a letter with your name on it is about to be delivered — including your second stimulus payment.

It can take three business days to activate your account after you set it up. Once it’s live, you will receive an email each morning, Monday through Saturday, if mail is scheduled to arrive, notifying you of mail that will be delivered, along with a grayscale image of the front of the letter. You can also use the free Android and iPhone Informed Delivery app to be notified.

Just be aware that it will show you all your documents scanned by the post office, not just your stimulus payment. You can cancel the service at any time.

How do I know I’m getting my second stimulus check in the mail?

If you didn’t already set up direct deposit with the IRS, this is the most likely outcome, as long as you’re eligible to receive a second stimulus check. The IRS has opened up its online tool to track your second check’s payment schedule, but will not activate the feature that will accept new direct deposit registrations.

Informed Delivery: Quickly make sure you can sign up

When the USPS runs mail through its automated mail sorting equipment, it creates a digital image of the front of all letter-size mail, and that includes your stimulus check. The Informed Delivery program uses this digitally captured information to notify you when each piece of mail is on the way.

The service is available to many residential and personal P.O. box addresses but not businesses. It also won’t work for some multiunit buildings where the Postal Service hasn’t yet identified each unit.

To check whether it’s available in your area, head to the Postal Service’s Informed Delivery page and tap the Sign Up for Free button. Then enter your mailing address, and tap Continue. If the service is available, you can then set up an account.

Set up Informed Delivery like this to track your mail

Setting up your account is straightforward.

1. On the Postal Service’s Informed Delivery page, tap Sign Up for Free.

2. After you enter your mailing address and confirm it’ll work with the service, you’ll need to accept the terms and conditions and tap Continue.

3. On the next page, choose your username, password and security questions. Then, enter your contact information and tap Continue.

4. On the next page, you’ll need to verify your identity. Tap Verify identity online if you want to receive a verification code on your phone or tap Request invitation code by mail if you want the Postal Service to mail you a code. If neither method works, you may also have the option to visit a post office to verify your identity in person.

For more stimulus check details, here’s how to calculate an estimate of your total, what we know about a third stimulus check and how some of your rights have changed for the better with a second stimulus check.