Salary Deferral contribution timing

This plan is 401(k) their are 4 participants

2 hce and2 nhce's

Have a corporate ext receive earned income

I am working on the 12/31/2023 plan year end. 

Do the hce's have until the due date of their corporate return 9/15/2024 to make their salary deferral contribution for the 12/31/2023 plan year end

2 hours ago, alwaysaquestion said:

Do the hce's have until the due date of their corporate return 9/15/2024 to make their salary deferral contribution for the 12/31/2023 plan year end

No, they do not. HCEs don't receive any special treatment when it comes to deposit timing.  Are you asking about self employed individuals? If so, then this thread may help.