You can find the CP or LTR number on the right corner of the letter. Tax audit letters will include your name, tax ID number or Social Security number, employee ID number, address and contact information.It's just an extra step we're taking to verify the returns we process and make sure refunds go to the right person. A few "must knows" for taxpayers to learn before starting the Free File Fillable Forms program. For more information on obtaining a letter of determination from IRS, visit the IRS Web site. It doesn't indicate whether you were required to file a return for that year. Freeze Out Fraud This Holiday Season. Scammers and fraudsters often pose as employees of Virginia Tax, the IRS, or other government agencies. Sign and date the form once you have filled in these lines. Completing these steps helps to protect your privacy.