SEP IRA - Is timely contribution made ineligible if tax return is not filed on time?

[mountain17]

I own an LLC filing as S-Corp to which I am the sole employee.

If I make a SEP contribution ON TIME, before the filing deadline, but then file the Tax Return itself late (both the 1120S + 1040), would the late filing in any way cause the SEP contribution to be disallowed? 

I've read and searched every IRS retirement account rules and info page (about 10 documents) and see nothing other than the rule that it must be contributed before the filing deadline, including extension.   My tax preparer thinks it's not allowable, but SEPs can be for hundreds of employees of a C Corp, imagine the corrections nightmare to all of their taxes if the Corp filed late, and no fault of the employees? That does not seem correct, and not including it would be a significant tax burden as it's already late.  There are not so many tax rules which are disallowed due to late filing other than some credits and special depreciation methods that I know of.  Thanks!

[fanfare]

If you met the deadline for your eligible retirement plan contribution, then when you file your tax return for that year is irrelevant.

@mountain17 

[dmertz]

Just be aware that for a calendar-year S-corp the filing deadline was March 15, 2023, so the SEP contribution had to be made by that date because you did not request a filing extension.  As long as the contribution was made by that date and was no more than 25% of the compensation shown on your W-2 from the S-corp, you are fine.

[Mike9241]

ask the tax preparer to show you the law that says it's not allowed since the timeliness requirement applies only to the contribution not the return.