According to the US National Taxpayers Union (NTU) the US has lost billions of hours of productivity owing to the burden of compliance with the complex tax code. The NTU has computed the total cost of tax compliance at USD224.3bn a year. This includes expenses such as the need for individual taxpayers to purchase tax software and to expend other costs in order to complete their tax returns. The NTU has looked at expenses of preparation and submission of returns including postage and photocopying expenses. The US Treasury also has a high compliance burden as a result of the paperwork required by the complexity of the tax laws. The task of completing the annual tax return is generally the largest and most time consuming task that a citizen must complete for the government, and the NTU suggests that there is more room to simplify tax compliance.