The mistakes are:
- A failure to sign Form 5330;
- Using an invalid plan number, or leaving the plan number blank;
- Using one Form 5330 to report two or more excise taxes that do not have the same filing due date and thus may not be filed together;
- A failure to complete lines 12a-12c in Part I (Summary of Taxes Due) when there is tax reflected in Line(s) 1-11;
- If Part VII (Tax on Prohibited Transactions (Section 4975)) is applicable, a failure to check the appropriate box on Line 26a (discrete or not discrete prohibited transaction) and Line 27 (corrected all prohibited transactions); and
- Confusing the relationship between Part VII (Tax on Prohibited Transactions (Section 4975)) and Part IX (Description of Correction) of Form 5330 (Retirement News for Employers, Summer 2004).
More information about Form 5330 can be found here .