Financial Accounts Reporting (United States of America) Regulations 2014
5 Obligation of a reporting financial institution to register
(1) Every reporting financial institution shall, for the purposes of complying with Article 4(1)(c) of the Agreement, register with the Internal Revenue Service of the United States of America for the purposes of FATCA in such manner, including by electronic means, as the Internal Revenue Service may require.
(2) An application for registration shall be made by the reporting financial institution not later than 31 December 2014 or, where the institution is not a reporting financial institution on that date, not later than 30 days following the date on which the institution becomes a reporting financial institution.