My first thought, of course, is why not?
This is someone you already obviously trust or they wouldn`t be handling your personal finances. Why would you need a different person to handle your business?
Is there a problem with your existing relationship? Some reason why you wouldn`t want the same person taking care of everything?
Very glad to hear the relationship is good.
There will be times when your personal finances will overlap into the business and vice-versa. You`ll need someone who can tell the difference.
Most startups begin by using their personal accounts for business expenditures but, at some point, you`ll want to keep them separate ~ your existing accountant/bookkeeper should recognize and be able to questions new types of expenses almost immediately.
I think you`re on the right track. Best of luck in your new venture.
In my opinion, I think you would be safer to have separate accountants for your personal income and your business income (unless you are sole proprietor). I used to work for a tax accountant and he had many clients for whom he did both their personal and business tax filings.
After 2 years, I found that he was concealing some of his clients business income and filing slightly false tax reports because he didn`t throughly analyze their financial records. He opened up his clients to more risk. If his clients had separate accountants for their personal finances and their business finances, then one accountant would be able to provide oversight on the other (and vice versa). Using a larger accounting firm would probably also minimize the risk.