In Luxembourg, your tax number is not included on official identity documents. However, this 13-digit number can be found on your social security card.
In France, the tax identification number (TIN/NIF) is assigned when the person is registered in the tax authority’s databases. This 13-digit number is also known as the “reference tax number” (or “SPI” number, which stands for “Simplification of Tax Procedures” in French). This reference tax number can be found on your pre-filled income tax return, and on your income, housing and property tax notices.
In Belgium, the TIN is the 11-digit national number (NN). It is usually found on the back of your ID or social security card (SIS card).
In Germany, the TIN is not included on official identity documents. The 11-digit Identifikationsnummer has existed since 2008. It can be found in the letter relating to the allocation of this identification number (Mitteilungsschreiben über die Zuordnung einer Identifikationsnummer).
For other countries, please contact your local tax authority.