Use the Cash Book settings to choose a default bank account to be used when raising sales, purchase and nominal payments and receipts.
You can select a blank entry for the default bank account. In this case, you must choose the bank account you want to use when raising nominal payments and receipts. If you selected a blank entry for the default bank account, the first base currency bank account in the Cash Book is used by default when you raise payments and receipts in the sales and purchase ledgers. You can choose a different account, if required.
You must have:
Open: Cash Book > Utilities > Cash Book Settings.
Open: Cash Book > Utilities > View Cash Book Settings.