Any debt can be sold to a debt collector and their collection of the debt is independant of the original defaulted debt. Say you owed the bank the last 4k of a loan and couldn pay it back, if the bank wrote the 4k off they would sell the debt to a collection agency for maybe €100 (guesstimate) The agency will then look for the 4k from you using threats that will not be initiated, this is my experience anyway, I even got the ICB report stating that debt was written off, debt collector got minimal amount from me, just didn't pay them anymore and they never came after me, probably recovered their cost of debt from me and let rest go. I would fear them anymore anyway thats for sure.