Your case will usually be handled by a court official who deals with bankruptcies and liquidations, known as an ‘official receiver’.
They might hand the case over to an insolvency practitioner - a lawyer or accountant who specialises in debt recovery.
The official receiver or insolvency practitioner might also be called:
the ’trustee’ in a bankruptcy
the ‘liquidator’ in a company liquidation
Read the guidance on what happens after you’ve registered as creditor.