A2: Ancillary powers
“(1) The Commissioners may do anything which they think—
(a) necessary or expedient in connection with the exercise of their functions, or
(b) incidental or conducive to the exercise of their functions.
(2) This section is subject to section 35.” (CRCA 2005, s.9)
“65.This section provides the Commissioners with ancillary powers to do anything necessary in connection with the exercise of their functions or incidental business. Examples are:
- the gathering of information relating to the exercise of their functions;
- establishing advisory bodies;
- entering into agreements;
- acquiring and disposing of property; and
- promoting, or assisting in the promotion of, publicity about the tax system.” (Explanatory notes)
Ancillary powers cannot be used to override statutory requirement
"Although the ancillary powers listed are simply examples and are by no means exhaustive, I think they give a much better flavour of the type of incidental or ancillary powers that Parliament would have had in mind when it came to enact s.9 CRCA. Certainly, none of the examples would suggest that s.9 CRCA would have the effect that HMRC’s practice of accepting voluntary returns as returns made under s.8 TMA (even though no notice to file a return had been given under s.8(1)) was, as Ms Nathan put it, “clothed with the force of law.” (Patel v. HMRC  UKFTT 185 (TC), §130, Judge Brannan).
Absence of express power points against ancillary power
...It cannot be said, therefore, that the review and appeal provisions were drafted without heed to the possibility that HMRC/the FTT might need powers to allow relief pending appeal, but when it comes to ancillary decisions such as the decisions in question here, there is nothing in sections 13A-16 of FA 1994 (see above at para 23 et seq), or in the Tribunal Procedure (First-tier Tribunal) (Tax Chamber) Rules 2009, conferring any power on either HMRC or the FTT to suspend, or circumvent, the consequences of the decision that is being challenged pending determination of the appeal.
 R (Wilkinson) v Inland Revenue Comrs  1 WLR 1718 offers some insight as to how this absence of express power might bear upon the operation of a general provision such as section 9 of the 2005 Act. It concerned bereavement allowance, which at that time was payable only to widows and not to widowers. The House of Lords rejected the argument that section 1 of the Taxes Management Act 1970, which said that income tax “shall be under the care and management of the Commissioners of Inland Revenue”, could be construed as giving the revenue a discretionary power to grant an extra-statutory concession allowing a widower to claim the equivalent to a widow’s bereavement allowance. Lord Hoffmann observed at para 21, with the agreement of the rest of the House, that the power could not be construed “so widely as to enable the commissioners to concede, by extra-statutory concession, an allowance which Parliament could have granted but did not grant”. Although the context was not the same as in the present case, section 1 of the Taxes Management Act 1970 not being concerned with ancillary powers in quite the same way as section 9 of the 2005 Act, it can similarly be said here that section 9 should not be construed as conferring on HMRC a power to grant temporary approval pending appeal which Parliament could have conferred through Part 6A or the FA 1994, but did not. That temporary approval pending appeal is not part of the scheme is perhaps underlined also by the fact that express provision was made in section 54(12) of the Finance Act 2015 for the time from which the prohibition on trading in section 88C was to apply, namely when the wholesaler’s application to HMRC was “disposed of” (ie by section 54(13), has been determined by HMRC, withdrawn, abandoned, or otherwise ceases to have effect), rather than from the conclusion of any appeal against the decision on the application." (OWD Ltd v. HMRC  UKSC 30)