Journal entry

I wonder if someone can help me. 

I have a customer who organise festivals throughout the year. When they first began it was only two different ones, but now they have five or six different ones so I am finding having them all in one account is a bit troublesome, so need to create an account for each different festival.  However, last year they paid some deposits for festivals that didn't actually go ahead because of Covid so they are sitting in the "old" account.  This year they are planning their festivals and obviously want to use their deposits.  How do I remove the deposit from the old account and allocate it to a new account.  I assume its through a journal but would like some guidance if possible.  Many thanks