It is a good business practice that you maintain your book in a timely fashion. While IRS does not automatically require auditing of your book, you are required to maintain one when official audit is called. Also, banks may also request to look at your book when you apply for loans.
For most startups or investors, there will not be many entries. We provide a simplified bookkeeping solution that keeps all your records at a very economical rate. (Bookkeeping service is optional****. Please call us for details or check here.)