TCM0128060 - Eligibility - residency and immigration: Immigration status (Info)

Customers who are subject to immigration control aren’t entitled to tax credits unless

or

the customer or partner satisfies one of the exemptions from the general exclusion detailed in TCM0128040.

Customers are ‘subject to immigration control’ for these purposes if

they require permission to enter or remain in the United Kingdom (UK) and they don’t have it
their permission to enter or remain in the UK is subject to the condition that they don’t have recourse to public funds
their leave to enter or remain in the UK is given as a result of a maintenance undertaking (they are sometimes known as ‘sponsored immigrants’). A maintenance undertaking means a written undertaking given by another person (or persons), under the Home Office’s immigration rules, to be responsible for the maintenance and accommodation of the person in question
their permission to be in the UK has been extended to allow them to remain to pursue an appeal against a decision to vary, or not to vary that permission.

There are special rules for couples, as follows

where one member of a couple is subject to immigration control and the other member isn’t subject to immigration control, the couple should be treated as if neither of them were subject to immigration control
where one member of a couple is subject to immigration control and the other member is also subject to immigration control but satisfies the conditions for one of the exemptions from the general exclusion, the couple should be treated as it they were both covered by this exemption.

The immigration status of a child or qualifying young person isn’t relevant for tax credit eligibility purposes.

Tax Credits Manual