The need to separate Business and Personal Expenses!
First of all, the idea behind separating business expenses from personal expenses is that it provides adequate tracking as to how much monies have been spent on business expenses.
You should run all direct business expenses (that is all items of expenses that are directly related to business) through the business account. Further, in your case, perhaps at this time you should consider paying all your cell phone, internet subsription dues and items of expenses that are also partially business from your business account.
At the end of the year, you can discuss with your CPA that these were partial expenses for business, and let him determine the non-deductibility of these expenses. My point is that it is better to have captured these partial business expenses into your business disbursement checks or bank statement, because you wont forget to claim these expenses.
In short, the CPA might determine the entire amount of these is really business and so it might be 100% deductible for business.
Really, in most cases, most small businesses deduct all the internet and cell phone expenses in their entirety except for the auto, which is based strictly on percentage of business use.
I hope this helps you!