A Tax Identification Number (TIN) is an identification number used for tax purposes.
In some countries, TINs are found on official identity documents (such as ID cards, passports, driving licenses, etc.) and usually match the personal number.
In other countries, TINs are specially issued by government institutions to those who submit a tax return form. In this case, TINs can be found in other documents (such as health insurance cards, civil tax evaluation forms, etc.)
Some countries do not issue tax identification numbers to their taxpayers. Their tax authorities use other data to identify taxpayers (such as name, date, and place of birth, address, gender, etc.).