Use the accounts setup options to control:
- Overdue account locking - prevent new sales being created for customers that have gone over their credit limit
- Locking of matched transactions - prevent editing of bank transactions that have been matched
- Invoice numbers - specify the last number, and therefore the next number used
- Cost of sales accounting - switch it on or off
- Tax and due dates - for sales invoices
- Default email address for accounts - if there is no accounts email on a customer record use the main email address when creating quotes and orders
To see what's available and change your settings go to Setup > Company > Accounting: Options.
