Form 5330 due date calculator
Pick the month and year your employer’s tax year ends, and read the exact filing deadline the IRS instructions set for a late 401(k) deposit’s excise tax return.
Most calendar-year 401(k) plan sponsors pick December of the current year.
This is the general filing deadline only. An uncorrected late deposit is treated as a new prohibited transaction each succeeding tax year, so an open failure can mean another Form 5330 due the following year, not a one-time filing, and the extension request now goes on Form 8868, since Form 5558 stopped covering Form 5330 in December 2025. Read the full mechanics, including the worked multi-year example and the 403(b) carve-out, in When is Form 5330 due for a late 401(k) deposit?.
This tool is independent research, not legal or tax advice. Verify a filing deadline against the current Instructions for Form 5330 before relying on it.