Most small business owners are very good at what they do but not good at accounting. Don't Force your self to do something you hate.
2) Increased costs. Less time in the field.
3) Lack of efficiency.
Think about it it takes a long time just to get organized and than you only do it once a year. It normally takes a small business owner 3 to 4 times longer than a CPA to do accounting work. Lets say you are a plumber making $86.00 dollars an hour you can find a true CPA professional to work for $115.00 an hour and a less qualified CPA for under $86.00. You are looking at huge saving's. The average tax return for a business can be completed in less than 10 hours and is under $1000.00. I have preformed accounting for much less with simple returns.
4) missed deductions.
If you don't understand what you are doing it is very easy to miss something. For instance all capital leases can be written off, did you do that. I'm not going to list everything but a CPA does not miss valid deductions so use one.
5) Tax abuse, IRS Audits :(
Many business owners take too many deductions to compensate for all the ones they forget. Business throw up huge flags and get audited adding frustration and increased costs. Sometimes the IRS will audit back multiple years after they discover a flag. Save yourself time and headaches. Do the right thing get a CPA.
I have plenty more but if you hate accounting and bookkeeping frustrates you, outsource it. If you love numbers and always dreamed of being an accountant have a CPA review your return, it's cheap and can be done in many cases for less than an hour of billing. A CPA can help you find things you missed.
Don't get audited have a CPA prepare your business tax return.