Estonian: Isikukood (IK) Digits: 11-digit Format: XYYMMDDZZZQ Found on: Estonian ID card or passport Tax documents Healthcare and social security records Official correspondence • https://www.oecd.org/content/dam/oecd/en/topics/policy-issue-focus/aeoi/estonia-tin.pdf • https://www.emta.ee/et/kontaktid-ja-ametist Finland Personal Identity Code; Finnish henkilötunnus (HETU) For individuals, it consists of 11 characters: - 6 digits - 1 character which can be + (plus), - (minus) or the letters Y, X, W, V, U,