Processing the Lock-in Modification

All jobs must be modified from the Step 2 checkbox withholding (higher withholding) to the standard withholding rate UNLESS the taxpayer is presenting a frivolous tax argument. See IRM 5.19.11.10.5, Frivolous Communications.

Use the WHC Withholding Estimator to compute the amount of annual credit or additional tax that will be withheld per pay period from the taxpayer’s wages.

When processing a modification to the lock-in rate, inform both the taxpayer and employer. Send Letter 2808C to all employers considered in the Modification and send Letter 2812C to the taxpayer.

Caution If the taxpayer has more than one employer, verify the amount shown as an annual credit or additional tax is correct for each employer based on the WHC Withholding Estimator results for each.