Deductions that are too late to deduct during an audit

[Mary Jay]

Hi guys,

I never claim my home office on my taxes and I was thinking that when I have an audit, and the audit finds something, then I can use the unclaimed home deduction to offset it.

But then Ive heard that some deductions are not allowed to be claimed during the audit , because its too late. (Not sure if the home deduction is one of them)

What are the tax deductions that are too late to deduct post filing taxes (during audit)