I purchased a new desktop computer system for my small business, and since the computer is in my home (I don't have a separate office, and while I do have a room in my home devoted entirely to office/business use, I haven't been taking the home office deduction), I believe it qualifies as "Listed Property." I use the computer almost exclusively for business, but I do use it to watch the occasional movie (because the screen is much bigger than the one on my new laptop that I bought mainly for personal use and that I'm not deducting) and read/respond to occasional personal emails that come in while I'm working. I know that means I'm supposed to keep written records of my business vs personal computer usage, and I assume it's those written records that Form 4562 Part V Line 24a "Do you have evidence to support the business/investment use claimed?" and Line 24b "If 'Yes,' is the evidence written?" refers to?

What happens if I answer question 24a with "No"? Will my deduction not be allowed? If I answer "Yes," will I be expected to enclose written evidence with my tax return? If not, will the IRS contact me later to request my written computer usage records? About 90% of the time I use the computer for business, but I learned only recently that I was supposed to keep a written record of when that is, so I would have to go back and construct such a record from memory and document/email dates as best as I can. That would be a lot of work, not to mention enormously time-consuming.

I'd also like to hear from other sole proprietors who took a Section 179 deduction for a computer that qualified as Listed Property. Did you have written usage records if you did not use the computer entirely for business? Did the IRS ask to examine them? How detailed were they?

Any help would be much appreciated.