# Invoices

The invoice represents the business transaction between you and your customer. In Resolve, an invoice must be tied to a customer and an advance can be taken on the invoice.

For an advance to be taken on the invoice, a PDF of the invoice must be uploaded and the associated customer must be approved and have available credit for the amount of the invoice.


## List all invoices

 - [GET /invoices](https://docs.resolvepay.com/merchant-api/openapi/invoices/listinvoices.md): Return a list of invoices.

## Create an invoice

 - [POST /invoices](https://docs.resolvepay.com/merchant-api/openapi/invoices/createinvoice.md): Create a new advanced or non-advanced invoice with the desired terms.

## Fetch an invoice

 - [GET /invoices/{invoice_id}](https://docs.resolvepay.com/merchant-api/openapi/invoices/fetchinvoice.md): Retrieve an existing invoice by its ID.

## Update an invoice

 - [PUT /invoices/{invoice_id}](https://docs.resolvepay.com/merchant-api/openapi/invoices/updateinvoice.md): Update an invoice.

## Delete an invoice

 - [DELETE /invoices/{invoice_id}](https://docs.resolvepay.com/merchant-api/openapi/invoices/deleteinvoice.md): Delete an invoice.

## Send an invoice

 - [PUT /invoices/{invoice_id}/send](https://docs.resolvepay.com/merchant-api/openapi/invoices/sendinvoice.md): Send an invoice to the customer.

## Void an invoice

 - [POST /invoices/{invoice_id}/void](https://docs.resolvepay.com/merchant-api/openapi/invoices/voidinvoice.md): Void an invoice.

## Cancel an invoice

 - [POST /invoices/{invoice_id}/cancel](https://docs.resolvepay.com/merchant-api/openapi/invoices/cancelinvoice.md): Cancel an invoice.