Search only in titles Manage VAT Invoices by Period for Main Contractors Navigate to the Manage VAT Invoices by Period Page From the Compliance menu at the top of the Project Home page, select Manage Periods by Period. From the drop-down by the organisation's name on the Manage VAT Invoices or VAT Invoice Status page, choose the Manage VAT Invoices by Period link. Next: Add Sub-Tier for Main Contractors