Request for information and returns
19.  The Board may, by notice in writing, require —
(a)any person to furnish, within the time specified in the notice or such other extended time as the Board may allow, any information that may be required by the Board for the purpose of inquiring into or ascertaining that person’s or any other person’s liability under these Regulations; or
(b)any self-employed person, within the time specified in the notice or such other extended time as the Board may allow, to complete and deliver to the Board any return specified therein including a return of income for any relevant year or any other previous year.