Making it easier to pay taxes

My idea is for a tax system that makes it easier for sole traders and small businesses to pay their taxes as they go without the worry of larger quarterly instalment bills and or large tax return bills. What I would like to see is a simple tax bracket system based on earnings as you go rather than predicting your future earnings which may not be accurate.

For example for every invoice payment from a client received from a business a simple percentage system put on that invoice which can pay directly to your own ATO account for that one financial year, this is then accurately calculated at the end of the financial year with your tax return and no doubt less of a debt resulting with the credit in your tax account.

This keeps paying taxes simple and allows the user to pay their taxes when they have been paid and have the money to do so. There is currently a problem with small businesses (like myself) who struggle financially with low earnings experiencing high end of year tax bills which have resulted in a system that inaccurately predicts earnings of the future and bases tax of this. In my opinion tax should be paid on what you earn as you earn it under a tax bracket and to help this a simple system to be in place for a "Pay per invoice" to be sure a percentage of what is earned is going to tax allowing credit to an account for the end of the financial year. This would reduce the problem of tax debts in Australia which is no doubt costing Australian tax payers money. This also helps to keep the system less complicated, pay as you earn and easy to use would reduce the problem of tax debt considerably.