https://www.citizensadvice.org.uk/wales/debt-and-money/help-with-debt/dealing-with-your-debts/check-if-you-have-to-pay-a-debt/
Check if you have to pay a debt - Citizens Advice
How to check liability for a debt, including time limits on debts and how to challenge a debt you think you might not be liable for.
to pay a debtcheckcitizensadvice