A couple of carve outs by the Australian government on the scope of the liability levy on five banks amount to a concession to the sector following a noisy, if short, consultation.The Major Bank Levy Bill - introduced to the House of Representatives yesterday by Treasurer Scott Morrison will, in line with the budget proposal, "introduce a levy on ADIs with total liabilities of greater than A$100 billion."The $100 billion threshold will be indexed to grow in line with nominal GDP.The explanatory memorandum for the bill confirms that the levy is imposed at a rate of 0.015 per cent on certain liabilities of the ADI that are reported to APRA each quarter. The amount of liabilities on which the major bank levy will be payable is the total reported liabilities of the ADI for the quarter, reduced by the sum of:- the bank's total Additional Tier 1 Capital at the end of the quarter;- the bank's total holdings of deposits protected by the Financial Claims Scheme at the end of the quarter;- an amount equal to the lesser of the derivative assets and derivative liabilities at the end of the quarter in relation to the ADI; and- the exchange settlement account balance held with the Reserve Bank of Australia for the quarter in relation to the ADI.The first two deductions are consistent with the scope of the tax as set out in the Budget earlier this month.The second two deductions are concessions allowed in line with concerns voiced by banks during the ten days or so in which banks had access, confidentially, to the draft bill.Treasury is giving no ground on the projected value of tax that the levy will generate. The estimate remains $6.2 billion over four years, even though the sum of estimates on the tax payable by the four largest banks sums to only two thirds of this amount.APRA will create a new reporting form to collect the data required to calculate the major bank levy.Treasury also yields no ground on other debating points."Any risks to financial market disruption arising from the major bank levy have been minimised by its design," the Explanatory Memorandum states.In addition: "The major bank levy should have a negligible impact on the real economy," it said.Anna Bligh, chief executive of the Australian Bankers Association yesterday again queried the value of the likely tax take."Treasury has not provided sufficient modelling to explain their calculations in the budget. At this stage, we are still uncertain just how much the levy will raise," she said.