noun
taxpayer identification number
Refers to a taxpayer ID number, typically in the context of the US, Germany, or similar systems. Not a Japanese domestic term.
アメリカでは、納税者番号として社会保障番号が使われることが多い。
In the US, Social Security numbers are often used as taxpayer identification numbers.
Compound of 納税者 (taxpayer) + 番号 (number).