To be clear the employer already has employees' SSN, but in declining a new enrollment with 401k benefit, which requests (among other things) an SSN. Is one in any way obligated to give them this info? Is the employer allowed to? Would they (The 401k supplier) have any good reason for it?
Edit: This not stopping a current deduction. This is an initial enrollment. Also this is not about my company specifically but any employer in the US which does not qualify as a small business. Nor is it about a specific 401k provider, but about any new 401k program starting at such a company.
( 6 months ago )
The issue is that you work for a company that has setup their 401K retirement program with automatic enrollment. To stop the process from starting or to end the automatic deductions they need you to fill out a form.
Many companies refer to you either by employee number or by social security number. Your employer does have social security number due to their payroll requirements.
The company running the 401k generally needs a taxid number for every account. This goes for IRA accounts, 401k accounts and non-retirement accounts.
Your name on the form is not good enough, the company running the 401K may need to be able to document your declining. They may even have to refund your initial contributions in some cases. Your employer and their payroll processor needs to turn off the deduction. Your employer may need to prove to the feds that every employee was initially enrolled in the retirement program but some declined.
Keep in mind that HR can just add your SSN and pass it to the 401K company. If your work for a small company your name alone may be enough for HR to 100% identify you. For a large company they will need your employee ID number. Of course it might delay the stopping for a paycheck or two.