Universal Credit and child maintenance
Since April 2010, child maintenance payments are fully disregarded when calculating Universal Credit. This means any child maintenance you receive does not reduce your Universal Credit entitlement at all - you keep every penny of both.
How much child maintenance do I get on Universal Credit?
Your Universal Credit award is calculated without any reference to child maintenance income. So if you receive £200/month in maintenance, your UC remains exactly what it would be without maintenance. They are treated as completely separate.
Tax Credits and child maintenance
Child maintenance is also ignored for Working Tax Credit and Child Tax Credit purposes.
Housing Benefit
Child maintenance is not counted as income for Housing Benefit calculations.
Does child maintenance affect the paying parent's benefits?
Child maintenance payments you make are not deductible from your income for benefit purposes. However, if you are on certain benefits (such as Income Support or income-based JSA), the CMS will only charge you the flat rate of £7/week.
Child Benefit
Child Benefit is not affected by whether maintenance is being paid or received.