I am a Writer who will soon publish a book about my true adventures climbing the seven summits. Can I list the costs of those climbs as Startup Costs?

[Phillip1 · Accepted solution]

Unfortunately not very likely. 

When taxpayers take expenses that are usually considered a hobby, and try to deduct those expenses as business expenses, the IRS usually takes a hard look at those expenses. Hobby-type expenses can be disallowed for reasons as broad as:

1. The expenses are not reasonable and necessary.
2. There is a high degree of personal enjoyment from the expenses.