From the Experian site, "How long does a default stay on your credit file?
A default will stay on your credit file for six years from the date of default, regardless of whether you pay off the debt. But the good news is that once your default is removed, the lender won’t be able to re-register it, even if you still owe them money. Nevertheless, you should continue to meet any remaining payments as the lender could go on to register a CCJ against you.
Note that the lender may sell your debt to a debt collector (a company that specialises in getting debts repaid). However, the lender must make this obvious on your credit report, so it won’t look like you have two defaults. Also, the amount and date shouldn’t change, so you won’t need to pay more or wait longer for your default to be removed."