When you create a new Account, it will, by default, have Invoice Settings that match your Company defaults (Settings > Company Information > Accounting). These settings can be customized for each individual Account. Navigate to a Client account then click Edit. Select the "Billing" tab. The following fields can be edited from the Company defaults:
Send Invoice By determines whether Invoices need to be emailed, printed, or both. Billing Terms will set how soon the Account's Invoices show as "Past Due". If this is set to "Due on receipt" then Invoices will show as "Past Due" as soon as they are generated unless the Invoice date is in the future. When to Invoice determines how frequently Invoices are generated. If this is set to "Monthly" then any Jobs completed in a calendar month will appear on a single Invoice at the end of the month. If this is set to "Daily" then an Invoice will be generated each time a Job is completed.
These settings will appear here on Invoices:
Additionally, you can change the AR Account from the Company default as well. If you want to change this, it can only be done on an Invoice by Invoice basis. This field does not pull into any pre-made reports in SA but it can be a field used in a custom analysis. It may affect your general ledger if you sync with QuickBooks.