business owner and partner spnsor a SIMPLE IRA
Unforuntately the owners never made the required 3% match to eligible employees as well as their own account
The owners are aware they must make up the missed match plus interest to the eligible employees.

Question:
Are they (owners) required to make up the missed match for themselves?

Are the make-up contributinos (for prior plan years) eligible for a tax deduction? I thought I remember seeing somewhere that a tax deduction as only allowed if the match was made by December 31 of the following year.

Thank you