All citizens want to pay the lowest amount of tax possible. For most individuals who work as employees there is very little opportunity to do anything with their tax level. Income tax is deducted at source, sales taxes are deducted on goods and services being acquired and all the other fee-based taxes are levied based upon the action that we take. Some owner managers feel that because there is more latitude when you are running your own business that it is acceptable to deduct in the business expenses that are not appropriate or worse not report all income.
Most democratic countries have a system of taxation, which is based upon self-assessment.
The government does not know how much money it is owed by you until you report it on your tax return at a fixed time each year. The self-assessment system requires that taxation be clear and easy to determine for all citizens and that the citizens feel that the system is fair. If a taxpayer takes advantage of the system and does not report all the income that they should then others bear the burden of making up the difference. To maximize the correct reporting of tax and minimize any attempts to not report the correct amount each tax department levies significant fines and penalties for any taxpayer found not correctly completing their tax filings. If they believe that the errors were deliberate then there are provisions to send the taxpayer to jail.