In the UK there is a staute of limitations.
This means that if you go for more than 6 years without making a payment or acknowledging the debt, then they cannot take Court action to recover it. This does not mean that you don't owe it, just that they can't recover it. However if at any time, you make a payment or acknowledge the debt the clock starts again.
If they get a Court order during the 6 years then the order is enforcable.
Debt companies often start court action after the 6 yrs in the hope that you may not know about the Statute. (The Court won't tell you about it, and if you do not enter it as a defence then you will lose)
12 years in the case of mortgages etc.