Have you heard of someone with national status receiving a 2801C IRS letter claiming it has been determined you aren't entitled to claim exempt status and that a "lock-in letter" was sent to your employer with instructions to begin withholding? That you are now selected for something called the Withholding Compliance Program?
If you have received an IRS letter 2801-C and your employer has received a lock-in letter, the IRS has determined that you're not entitled to claim exempt status or more than a specified number of withholding allowances.
See this web page:
https://www.irs.gov/individuals/understanding-your-letter-2801c
This is a link to information related to a "lock-in letter" and the "2801 C letter." The information provided at this website is specific to a "U.S. Citizen" but does have good general information.
You may want to confirm that you've completed ALL of the prerequisite steps required in establishing/declaring your "national" status. If you have not appropriately completed all the steps indicated in The Remedy section of the NationalStatus.info website, it is not too late.
It's critical that you respond to the IRS letter within the indicated allotted time. You'll need to inform them that you are working to declare your "national" status and, subsequently, become a "nonresident alien." You may want to request additional time to provide a more comprehensive response depending upon the number of steps still required to complete. If starting from the beginning by submitting your Affidavit of Citizenship Evidence to the United States Secretary of State, you may want to request a minimum of 6 months to complete the steps in the Remedy section. Remember to follow the steps in order and as the instructions indicate.
Once you complete the "3 STEPS TO FREEDOM" in the Remedy section, you can then reconnect with the IRS to request that they change their decision. Ideally, at that point they should not have any rationale to continue to withhold federal taxes.
