On the Terms / Pricing tab of a Customer account are a number of additional tickbox options ie
Order No Required: If selected, to post an invoice will require an order number to be supplied by the Customer.
International customer (GST Exempt): Accounts activated for this will have no GST calculated on Invoices and Quotes created for them.
No Statements: Selecting this option excludes the Customer from statement runs
Allow discount matrix pricing: This option allows discount matrix pricing to be activated / deactivated at the Customer level.