Missed Deferrals Less Than 3 months

A client missed starting an employee's deferrals and discovered the error less than 3 months later. The plan has a match. I understand that, being 3 months or less, no QNEC is needed but what about the match. Does anything need to be done about the missed match?

Employer must contribute full missed match, plus earnings on that match.

So, he will receive a match on the deferrals that he never made? Does it go in as a match? Or as a QNEC?

He will receive a match on the deferrals he never made.

https://www.asppa.org/News/Article/ArticleID/4784/IRS-Highlights-New-Methods-for-Correcting-Elective-Deferral-Errors 

They also need to issue a notice to the participant no later than 45 days after correct deferrals begin in order to be eligible for this correction method. Rev. Proc. 2015-28 describes the notice requirements.

New Methods for Correcting Elective Deferral Errors.pdf - Adobe Acrobat.pdf

I don't have time to look it up now, but I think if it is a safe harbor matching contribution, it is a QNEC, otherwise, it is just an employer nonelective. But don't trust my memory - I don't!

Nonelective is correct.