I just going to voice my pet peeve about this subject: Most people seem to think you automatically qualify for the $2500 de minimis election. That is not that case.
(1) You need to have decided on a SPECIFIC dollar amount (which may or may not be $2500).
(2) You need to have decided that at the BEGINNING of the year.
(3) You must have been treating those items under that specific dollar amount as fully deductible expenses for your 'books'.
I realized that those requirements are difficult to prove, so the the IRS would be unlikely to question it. But the rules do state that you need to have set up the 'plan' ahead of time (but you don't need to decide if you want to make the election or not until you file your tax return).
The taxpayer has at the beginning of the taxable year accounting procedures treating as an expense for non-tax purposes -
(1) Amounts paid for property costing less than a specified dollar amount; or
(2) Amounts paid for property with an economic useful life (as defined in § 1.162-3(c)(4)) of 12 months or less;
(C) The taxpayer treats the amount paid for the property as an expense on its books and records in accordance with these accounting procedures
https://www.law.cornell.edu/cfr/text/26/1.263(a)-1#f
