Means-tested benefits
Child tax credit (CTC) is not taken into account as income for income support, income-based jobseeker’s allowance or income-related employment and support allowance, although working tax credit (WTC) is.
Tax credits are taken into account as income for housing benefit. If a tax credit overpayment from a previous year is being deducted, the amount of the tax credit award less the deduction is taken into account. If you have been overpaid in the same year as the award and the tax credit award is consequently reduced, the lower amount of the award still to be paid to you is taken into account.
Arrears of tax credits are treated as capital for means-tested benefits and disregarded for 52 weeks.
CTC is taken into account when calculating whether the benefit cap applies (see here). If you or your partner get WTC, the benefit cap does not apply.