You should check the User Manual section to understand the basic process from creating, issuing, looking up to managing electronic invoices on the WinInvoice system.

Please check the invoice information you entered. If the error persists, you can: - Look up troubleshooting guides in the Troubleshooting section - Or contact WinInvoice support for timely assistance.

The validity period of the Wininvoice invoice package is “Unlimited” until all invoices are used. Electronic invoices issued in accordance with Circular 78 and Decree 123 that are not fully used within the year will be automatically carried forward by Wininvoice to the following year with a new invoice symbol, without requiring the Enterprise to take any action or notify the tax authority.

WinInvoice supports receiving, storing and managing input invoices, helping businesses easily look up, reconcile and serve accounting and reporting purposes.

You can look up invoices in the Invoice Lookup section by entering complete information as instructed to check the status and content of electronic invoices.

In case an issued invoice has errors, WinInvoice supports the following operations: - Invoice adjustment - Invoice replacement - Invoice cancellation Processing must comply with tax authority regulations.

Yes. WinInvoice ensures secure and safe data storage, complying with regulations on electronic invoices and information security under current law.