s 26 Power to obtain information or documents
(1) HMRC may by notice in writing require a person of a description specified in regulations to provide information or documents which HMRC require in connection with their functions under this Act. (2) HMRC may require a person to provide information or a document only if it is in the person's possession or power. (3) Regulations may make provision about notices under subsection (1), including, in particular— (a) provision requiring a notice to contain information specified in the regulations; (b) provision requiring, or enabling a notice to require, information or documents to be provided in a form or manner specified in the regulations or the notice; (c) provision requiring, or enabling a notice to require, information or documents to be provided at a time, or within a period, specified in the regulations or the notice; (d) provision requiring, or enabling a notice to require, information or documents to be provided in respect of a period specified in the regulations or the notice; (e) provision specifying descriptions of information or document which a notice may not require a person to provide; (f) provision about determining in specified cases whether information or documents are of such a description, including provision for that determination to be made by a person or body specified in the regulations.