hope you filed an extension for the business return. they're due today. not 4/18. for partnerships or S-corps the penalty is about $200/shareholder or partner for each month, or fraction thereof, that it is late. Businesses can request first-time penalty be abatement. frankly, sometimes we can't help because the bookkeeping is so bad.
you may want to spend the money on a pro to go over bookkeeping with you and advise on any other important matters that were handled incorrectly or cause tax issues.