For processing sales bookings in Exact Online you can use the following settings. These settings can only be accessed by users with sufficient rights (usually the environment administrator) via Manage / Environment / Administrations. Click 'Edit' and go to the tab 'Exact Online'.
Invoice number use as the entry number of sales invoices
With this setting it is possible to use the scanned invoice number of the invoice as the entry number in Exact Online. Do you use this setting and do the invoice numbers contain punctuation? You can filter these characters by activating the setting 'Remove non-numeric characters from invoice numbers of sales invoices'.
Invoice number use as Your ref. of sales invoices
With this setting it is possible to place the scanned invoice number of the invoice in the field 'Your ref.' in Exact Online. If this setting is selected, Exact Online will generate an entry number itself. To check for duplicate processing of invoices you can choose to activate 'Check if Your ref. is unique when exporting sales invoices'.