additional tax; penalty tax
A tax imposed on top of the base tax, often as a penalty for underpayment, late filing, or non-compliance. Used in legal and tax contexts.
If there is an omission in the tax return, an additional tax may be imposed.
The amount of the penalty tax is determined based on the tax that should have been paid.
Compound of 加算 (addition) and 税 (tax). The exact historical derivation is uncertain; the term is a modern legal coinage.