Search only in titles VAT Invoice Compliance Add Sub-Tier for Main Contractors Add a Manual or VAT Invoice Only Subcontractor or Supplier through the Add Sub-Tier page. Add Sub-Tier and Edit Sub-Tier Fields OverviewAdding a VAT Invoice for an On-System SubcontractorAdding a Manual Sub-Tier for Main ContractorsViewing an Uploaded VAT InvoiceNavigate to the Add Sub-Tier Page