Not sure which account you're expecting to decrease? Income is usually a credit and cash as an asset is a debit. Therefore, when you post cash sales sales becom...
You try adding jobs to your customers eg your main customer might be Joe Bloggs Ltd but he have a job added for Joe Bloggs (East), Joe Bloggs (North) etc..
I would enable classes for departments, you can then journal amounts between classes - same expense heading eg debit telephone class A, credit telephone class B...
Whilst the suggested answer could work, it will not work for those that are VAT registered. You can create a credit note going to bad debts instead, this system...
