# Invoice management
Use this document as a guide to help you manage and control your invoices when using services at GreenNode Service.
Here, we provide users with a comprehensive and detailed view of how invoices are processed at the GreenNode Service level, such as Invoice initiation time, Invoice information, Invoice payment time, and View invoice list.
## Invoice initiation time
Invoices are initiated in the following cases:
* Prepaid users perform actions that generate/change resource usage costs such as:
* Creating resources: Generate a new corresponding invoice for the initialized resource.
* Resizing resource configuration: Update information on the old invoice, generate a new invoice with the new configuration.
* Renewing resources: Generate a new invoice with the same resource configuration, but a different usage time.
* Recovery resources: Generate a new invoice with the same resource configuration, but a different usage time.
* The system records users' resource usage information at the end of each month for postpaid users:
* For postpaid users, one invoice will be generated for each resource to record the actual usage figures.
* In the case of users having multiple resources, multiple corresponding invoices will be generated for each resource.
## Invoice information
**Invoice information** includes the main information corresponding to a specific resource:
* Invoice code
* Invoice creation date
* Resource usage time
* Detailed description: Detailed description of the resource and usage configuration.
* Money amount
**For prepaid users**
The amount on the invoice is the amount that the user needs to pay to use a specific resource, calculated on the factors:
* (1) Resource configuration.
* (2) Unit price according to configuration (Discounted or not): At the time of performing the action on the resource (including VAT).
* (3) Resource usage time: Start date, End date (calculated by the minute).
* (4) Coupon deduction (if any).
For example, the formula for calculating the invoice value when initiating a Server including information is:
**For postpaid users**
* The amount on the invoice is the amount calculated based on the actual cost of using resources.
* The usage report will be exported at the end of the month on the user portal: .
* To understand more about how to calculate the cost of using resources in a month, please refer to this link.
## Payment due date
**For prepaid users**
The invoice will be generated immediately after the system successfully provides resources, and the invoice will be generated with a paid status at that time.
**For postpaid users**
After the service invoice is generated at the end of the month, users can pay in various forms:
* Exchange externally by transferring to the Sale Operation department.
* Pay directly on the user portal by depositing credit into the wallet.
## View invoice list
We provide a user portal website to help users manage usage invoices in the most efficient and effective way:
* Access the invoice management page here:
* To see more instructions on how to use and the features of the invoice management page, please refer to this link
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