Before sending your invoices to Sage Accounts, or exporting them, you can edit an invoice by pressing F2 or right clicking that invoice in the list and selecting Edit Invoice. This will display the Invoice Details window above.

Here you can change the company details and edit or delete charges by right clicking that charge.

You can also select another Sage account to use by clicking the browse button beside Account Number.

Once finished click OK to save the changes, or Cancel to cancel out without saving any changes.