@Python0608 wrote:
Is there any standard requirement for "reliable written record". Any examples? I'm thinking about creating an Excel sheet with columns like business, task, date and task time, will that be sufficient? I can add those time up and divided by the total time of computer on to figure out the business portion.
That sounds fine. "reliable" to the IRS generally means that the record was contemporaneous (meaning it was kept close enough in time to the actual event that your memory was fresh, and not something you made up the night before the audit 3 years later) and that your record is sufficiently detailed to determine whatever the record needs to prove. So for computer usage, date, time, and purpose (business or personal) would seem to cover it.
