The process of changing the way taxes are collected or managed by the government and is usually undertaken to improve tax administration or to provide economic or social benefits.

Tax reform can include reducing the level of taxation of all people by the government, making the tax system more progressive or less progressive, or simplifying the tax system and making the system more understandable or more accountable.

Numerous organizations have been set up to reform tax systems worldwide, often with the intent to reform income taxes or value added taxes into something considered more economically liberal. Other reforms propose tax systems that attempt to deal with externalities. Such reforms are sometimes proposed to be revenue-neutral, for example in revenue neutrality of the FairTax, meaning they ought not result in more tax or less being collected. Georgism claims that various forms of land tax can both deal with externalities and improve productivity.

Tax choice is the theory that taxpayers should have more control with how their individual taxes are allocated. If taxpayers could choose which government organizations received their taxes, opportunity cost decisions would integrate their partial knowledge. For example, a taxpayer who allocated more of his taxes on public education would have less to allocate on public healthcare. Supporters argue that allowing taxpayers to demonstrate their preferences would help ensure that the government succeeds at efficiently producing the public goods that taxpayers truly value.