When filing my business extension, how will I know if I owe taxes?

If your company maintains financial books/records, you can determine your current tax liability if you multiply your taxable income by the applicable tax rate. Many people simply use their numbers from last year’s tax return (as long as your tax situation is relatively similar). Remember to reduce your current tax balance by the amount of tax that was withheld (or paid via estimated tax payments), if any, during the year.