As far as I understand the Registrar can only make a repayment order on
the information that is to hand - usually the "means" form that has
been completed, along with wage slips or proof of benefit. It would be
up to the creditor to prove that the defendant had other money (or
income) from which the judgement could be paid.
The creditor could find out what bank accounts and credit cards are
held by the defendant from Experian - along with details of registered
debts and loans. However, that would not give them any idea of the
balance held in the accounts. It is also very unusual for a creditor to
go so deeply into defendants affairs as it is a costly and time
Generally, if a defendant is on benefit, the likely repayment will be
very low (£3 to £5 per month) regardless of the amount of the debt.
The amont will obviously be more if the person is waged - however, it
wil stil be a fairly low percentage. If payments are not made within
the terms of the judgement then the creditor can apply for the
judgement to be enforced and a court bailiff will attempt to sieze
goods - however, if the defendant won't pay, and has no visible assets,
it can be almost impossible to recover these debts. That is why many
companies just choose to write off debts below a certain amount - and
sell others on to debt collection companies for ridiculously low
amounts (often as low as 3%).
The only thing I would say is that if it was an individual chasing
another individual for a debt, then rationality goes out the windiw and
the plaintiff will often go to great lengths to uncover potential
sources for repayment.
For more information I suggest