Can you clarify the situation?

You first said "when applying for EIN", which is usually done at IRS.gov.  But then you sake if "return will reject", which seems to imply you are preparing the tax return (not applying for an EIN).

Can you clarify what exactly you are doing?

Schedule C does not use NAICS, it uses "Principal Business Activity" codes that are listed in the Instructions (they are based NAICS, but are often more broad).

Preparing tax return; used the filing set up documents as a guide. Sorry for confusion.

Because it is a farm activity (egg production),the IRS regs. indicate to File the LLC on Schedule F, not Schedule C. Software is accepting the SAIC code 112310 now.

Thank you so very much for replying!