Since 1 January 2016, Norwegian financial institutions have been obliged to record information regarding the tax residency of their customers and whether they are US citizens. They must also request the foreign tax identification number of these customers. The account information must be reported to the Norwegian Tax Administration, which will forward the information to the tax authorities in the customer's home country. The purpose of these rules is to ensure that financial income and assets in Norway are taxed correctly in the customer's home country. You may therefore be asked to state where you are resident for tax purpose, among other things.