A lock-in letter is a letter sent by the IRS (Internal Revenue Service) or state tax authority notifying your employer(s) that you did not withhold enough income tax by either filing exempt or claiming more allowances than allowed. This letter orders an employer to set your filing status and prevents the employee from making other withholding elections. Most individuals who receive a lock-in letter may only submit a new Form W-4 if it results in additional withholding.

Krucial Rapid Response will not be able to remove the withholding lockout unless we receive a letter directly from the IRS or relevant state tax authority specifying that you are no longer in the compliance program.

We recommend that you contact the IRS or state tax authority for more information.


View video, "What's a Lock-in Letter?"
VARIES BY STATE. Please contact your relevant state tax authority. The FTA has provided the following resource to assist in locating state government information.

How to get help

  • Call toll-free 855-839-2235 on weekdays between 8 a.m. and 5 p.m.
  • Fax documents to 855-202-8300 using either a fax machine or an online fax service. Several online fax services use the internet to send files from your computer or smart device to a fax number.
  • Write to:
    Internal Revenue Service
    Compliance Services
    Withholding Compliance Unit
    310 Lowell Street, Stop 837
    Andover, MA 01810