Last day to deposit employer contribution to individual 401K

[kevin_ny_2003]

Can you please confirm what is the last day to deposit employer contribution to individual 401K ( which is maxed at 25% of payroll amount for the year ) for FY2020? I understand the last day to contribute the employee part is Dec 31 . 2020. Is that correct?

Typically the individual 401 K plan provider does not distinguish between employee and employer contributions and I am concerned that if I deposit the employer part in Jan 2021 will that create any confusion?

Thanks

[dmertz]

The last day to make the employer contribution is the due date of your tax return.

The election to make an employee contribution for 2020 must be made by December 31, 2020, but the actual deposit of the employee contribution can be made soon after that date.  Department of Labor regulations dictate that the deposit be made no later than 15 days after the date that the employee contribution is deducted from the employee's pay.

[Dave1818]

So is that March 15th 2021, (for the employer contribution) the day corp returns are due? or May 17th (personal taxes due) or later (if there is an extension filed for the corporate the tax return)?