Friday night and looking for some Powers but this time not in a glass…

I am trying to think through a sort of half formed argument I have about tax credit processes which might be going nowhere.
There is a specific power in s4 of the tax credit act for regulations to be made prescribing the way claims can be made and reg 5 onwards in the claims and notifications regs seem to have been made in exercise of these powers. Reg 34 of the same regs sets out the way in which an annual declaration has to be made – in approved form etc - but I have not been able to find anything in s17 or elsewhere specifically giving the power to make regulations for this (doesn’t really mean its not there I can’t find anything these days: keys, phone etc.)
My question is: for regulations to prescribe a specific way of doing something like this does there have to be a specific power in the Act? And if so is there a power to make regs limiting how people can comply with the requirement to make an annual declaration?

Any thoughts appreciated

Are you looking for section 22(1)(b) of the Tax Credits Act?

That’s it thanks