Reporting late matching contributions

[SoCalActuary]

Generally, I work on DB plans, so forgive a naive question.

A 401(k) plan with matching by pay period has turnover in their HR department and some match deposits get missed. Later the TPA notes the failed match, and wants to make corrections. The issue is not resolved until 20+ months after the due date, but finally paid, voluntarily without govt direction.

How does this get reported for IRS, DOL and 5500 purposes?

What happens to the excise tax (under $100), specifically as to paying it to IRS or to participants?

Any help would be appreciated.

[jpod]

why an excise tax?

[SoCalActuary]

Under terms of the plan, payroll matching was required, but employer failed to make them timely for two years.

So was this failure to follow plan terms, or was the employer holding plan funds (a PT)?

[jpod]

I am not aware of any IRS or DOL position that delayed employer contributions = a pt.