Most states, with the help of USPS, sent ballot envelopes with a unique set of numbers for each individual voter. Those numbers are often known as Intelligent Mail Barcodes, which allow the Postal Service to track the ballot.
It's still too close to call a winner in these six states as votes continue to be counted: Alaska, Arizona, Georgia, Nevada, North Carolina and Pennsylvania.
If you submitted your ballot in one of these states and want to check its status, here's where you can go:
Learn how you can check your ballot in other states here.
And if ballot tracking technology isn't available where you live, you can contact your local election office if you have questions or concerns about your ballot.