@VivienJ

your step 4 is for the Memo, the bottom of the check, such as when you submit a bill payment to the phone company or the credit card company, they tell you to "please note your Account # in the memo." That is seen in Edit Vendor Name, for Account No on the Payment Settings tab.

The Voucher is using what you enabled and named the account in the Chart of Accounts. If you named it Checking, the Voucher prints Checking. If you named it Wells Fargo Account #12345, all of this is on the Voucher. So, you either Turn Off seeing account codes, print the checks, then turn on account codes; or, you Stop printing the details on the voucher entirely, which is the same place as @VivienJ describes, Print Account Names on Voucher = remove this option.