A tax code is a series of letters and numbers that are assigned to taxpayers by their country's tax authority. The code is used to determine the amount of taxes that an individual or business must pay.

For individuals, the tax code is used to determine their income tax liability based on their income and personal circumstances. The tax code typically takes into account factors such as the individual's income, exemptions, and deductions, and is used to calculate the individual's tax liability.

For businesses, the tax code can include regulations on corporate income tax, sales tax, payroll tax and other types of taxes. It also provides specific rules and exemptions for different types of businesses or industries.

Tax codes can be changed by the governing body over time to reflect changes in policy or economic conditions, so it's important for taxpayers to stay informed about any changes that might affect their taxes.