These three components form the basis for tax liability. Estimated tax payments are governed by Section 501, which states that interest will not be assessed if the sum of the estimated payments equals at least 85% of the liability and the amount of each estimated payment reasonably approximates the tax liability incurred during the quarter for which each estimate is made. Therefore, while a calculation must be made for the business income tax base, the gross receipts tax base, and the surcharge calculated with reference to those tax bases in order to determine tax liability, only one estimated payment of 85% of that liability need be remitted. There is no requirement to remit an estimated payment for each separate tax liability component.