The calculator works out an estimated entitlement to tax credits based on the information entered. However, because of the way tax credits work the amount someone actually receives may be different from the amount we calculate. Roughly one third of tax credits claimants are subject to an under or over payment, and their tax credit award can be adjusted for any amounts paid wrongly in the past.

Because entitlement to benefits takes into account income from tax credits, an accurate assessment must be based on the actual amount of tax credits currently being received. This question allows you to enter the current weekly amount of tax credits being received, so that entitlement to benefits can be worked out on the basis of actual income from tax credits rather than the amount we estimate.

The amount entered should be a weekly amount. If tax credit instalments are paid on a four-weekly or two-weekly cycle then the amount entered should be adjusted as appropriate.

In Pension Credit income from Child Tax Credit is ignored. Hence for people over 60 separate boxes are provided for income from Child Tax Credit and Working Tax Credit so that Pension Credit entitlement can be worked out accurately.

Arrears of tax credits paid as a lump-sum are counted as savings and, if relevant, should be included later in the calculator.