Legal background Freeze of certain social security benefits and certain tax credit amounts for four tax years
The relevant legislation is:
the Social Security Administration Act 1992, and
the Tax Credits Act 2002.
	Under section 150 of the Social Security Administration Act 1992, the Secretary of State for Work and Pensions is required to review the value of benefits and pensions in light of changes in prices. Where it appears to the Secretary of State that prices have increased relative to the value of those benefits the Secretary of State must make an up-rating order which increases certain benefits by at least the amount by which prices have increased and if the Secretary of State considers it appropriate, having regard to the national economic situation and any other matters the Secretary of State considers relevant, which also increases other benefits by such a percentage as he thinks fit. The Order is subject to Parliamentary approval. The Act provides that, for the four tax years from 2016-17, each of the relevant sums listed in paragraph 1 of Schedule 1 will remain the same as it was in 2015-16.
	Responsibility for up-rating child benefit was transferred from the Secretary of State to the Treasury under section 49(3) of the Tax Credits Act 2002. Therefore, the Treasury must review the child benefit rates for Great Britain in each tax year under section 150(1) of the Social Security Administration Act 1992 to determine whether or not they have retained their value in relation to the general level of prices in the United Kingdom. Section 150(2) of that Act provides that HM Treasury has a discretion, where it is considered appropriate, to up-rate the rates of child benefit taking into account the "national economic situation and any other matters" which "are considered relevant". Child Benefit is not devolved and applies to the whole of the United Kingdom.
	Responsibility for setting the amounts of tax credits lies with HM Treasury under sections 9, 11 and 65(1) of the Tax Credits Act 2002. The Treasury must review the rates in each tax year under section 41 of that Act to determine whether they have retained their value in relation to the general level of prices in the UK. Section 41 also obliges the Treasury to prepare a report of each review and include a statement of what each amount would be if it had fully retained its value, and to publish the report and lay a copy of it before each House of Parliament. Tax credits are not devolved and apply to the whole of the United Kingdom.