Note:

Regulations provide that the earliest the lock-in letter may be effective is 45 calendar days after the date of the letter. Letter 2800C requires that the employer(s) wait 60 days before adjusting the employee’s withholding to the filing status and withholding rate specified in Letter 2800C.

AMS documentation should include the basis for the WHC Withholding Estimator calculation, the specific information and/or all documentation requested from the taxpayer.