1 Understanding the Invoice Closing Problem in Sage 100 Accounting Hello! It's common to encounter situations where an old invoice in Sage 100 Accounting isn't properly closed, even after processing VAT, pre-tax (HT) amounts, and stamp duties on sales or purchases. This behavior may seem confusing, but there are technical reasons and management practices that explain it. Understanding why Sage doesn't automatically close these invoices is the first step to resolving the problem or addressing it effectively. 2 Impact on Editing VAT, Pre-Tax, and Stamp Duty Information When you edit elements like VAT, pre-tax amounts, or stamp duties on a sale or purchase, Sage 100 Accounting may not consider this action as finalizing the invoice. These edits are often perceived by the software as modifications or adjustments rather than final document validation. The system may require a specific action from you, such as generating a final journal entry or explicitly validating the invoice, to mark it as "closed." 3 Possible Causes of Non-Automatic Closing Several factors can prevent Sage 100 Accounting from automatically closing an invoice. These may include specific software settings that require manual validation for each document. Sometimes, the absence of a final journal entry associated with the invoice, or an entry that has not been fully reconciled and settled, can prevent the system from considering it closed. Additionally, internal business rules defined in your Sage configuration may influence this behavior, requiring manual intervention to confirm the closing.