You can convert the bank account to a sub-account by editing it in the Chart of accounts, ram16.
 
Here’s how:
 
 - Go to the Gear icon, then Chart of accounts.
 
 - Locate the account you want to edit.
 
 - Click the dropdown beside View register, then select Edit.

 
 - Tick the Make this a subaccount box.
 
 - Choose the trust account as the parent account.
 
 - Hit Save.

 
 
For more details, visit this article: Create subaccounts in your chart of accounts.
 
If you have further concerns, don’t hesitate to drop a comment below.