The standard period during which debts to the DWP can be reclaimed by them is six years.
If the DWP tries to issue a county court claim against you for an overpayment of benefit, and you think it is older than six years, you can put in a defence. However, if you’re planning to do this, you should seek legal advice.
As no court action is required, a direct earnings attachment can be used to recover benefit overpayments at any time, even after these debts are statute barred.