Amber - most NRPs don't pay? Where did you get that information?
It is easily found if you google.
From the Gingerbread site;
Only two-fifths (38 per cent) of single parents receive maintenance from their child’s other parent
Which indicates that the majority don't pay.
For all those with an agreement for child maintenance (both through the CSA and private arrangement) the median weekly amount received is £46 per family
Which indicates that this is data is collated from those getting CS from both CSA and private arrangements.
The average amount of child maintenance liable to be paid through the CSA is currently £33.50 per week (£22.50 if all cases with a weekly assessment of zero are included in the average
Which indicates that this data has been collated from those on 'zero assessments' too.
Among parents with care in receipt of income-related benefits, the average amount is £23 (excluding cases with a weekly assessment of zero
Which indicates there are single parents in that position who get no financial contribution from the NRP.
Of single parents receiving child maintenance through the CSA, 40 per cent receive less than £10 per week, 38 per cent receive between £10 and £50 per week and 22 per cent receive more than £50 per week
Which indicates that the majority get less than £10 per week, slightly less get somewhere between £10-50 per week. with a minority receiving £50+ per week.
There are approx 2 million single parents in the UK.
Which means that approx 760,000 single parents get no financial support from the NRP.
The sources for their data include stats from the ONS and DWP.