A taxpayer is a person or organization (such as a company) subject to pay a tax. Modern taxpayers may have an identification number, a reference number issued by a government to citizens or firms.

The term "taxpayer" generally characterizes one who pays taxes. A taxpayer is an individual or entity that is obligated to make payments to municipal or government taxation-agencies. Taxes can exist in the form of income taxes and/or property taxes imposed on owners of real property (such as homes and vehicles), along with many other forms. People may pay taxes when they pay for goods and services which are taxed. The term "taxpayer" often refers to the workforce of a country which pays for government systems and projects through taxation. The taxpayers' money becomes part of the public funds, which comprise all money spent or invested by government to satisfy individual or collective needs or to generate future benefits. For tax purposes, business entities are also taxpayers, making their revenues and expenditures subject to taxation.