Multiple deposits in the MyDeposit scheme

Hi,
I received a deposit from my new tenants early in the process and immediately registered it with MyDeposits to protect it. Being a first time landlord I was eager to follow the process.
However on going through the tenant check service because of an increased risk I wanted an additional months deposit. This has been paid, so I want to protect that as well.
Should I / Can I cancel the existing deposit and then reregister the larger amount or should I just add the extra on?