Expensing major repairs on tax return???

My first year in business I used ATBS on a trial basis because the company I was leased to paid for it for the first six months. They got my books in a big mess and made very little effort to straighten it out. I decided at that time that since I am the one making the money that I will be the one that accounts for it. Course I had had a lot of accounting and tax experience in my previous career, but that would be good advice for anyone without any accounting experience.