In the past the federal government used DUNs numbers to identify entities that it provides funding to and does other business with. Now they are assigning and using Unique Entity Identifiers (UEIs).
If you currently receive, and have been receiving federal funding, you most likely already have a UEI. You can find that by logging into SAM.gov. You should be familiar with that website because of contains other important resources.
If you will have a single audit for 2022, you will need your UEI to submit that audit report to the Federal audit clearinghouse.
SAM.gov will allow you to apply for a UEI, or update your information.
You may need documents to validate your request for a UEI, including a receipted copy of your articles of incorporation, your IRS exemption letter, or other documentation such as a bank statement or utility bill.