> ## Documentation Index
> Fetch the complete documentation index at: https://docs.slash.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Create and send invoices

> Issue an invoice now or on a date, keep it up to date, and set up what every invoice shows.

## Create an invoice

[Create an invoice](/api-reference/invoices/create) with a
[customer](/docs/v2/invoices/overview#customers), its line items and its
dates. Slash numbers it from your [invoice settings](#invoice-settings)
unless you send a `number`, adds up the totals, renders the PDF and emails it
to the customer right away with a link to the payment page (`payUrl`).

```bash theme={null}
curl https://api.slash.com/v2/invoices \
  -X POST \
  -H "X-API-Key: $SLASH_API_KEY" \
  -H "x-legal-entity: $SLASH_LEGAL_ENTITY_ID" \
  -H "X-Idempotency-Key: invoice-acme-2026-10" \
  -H "Content-Type: application/json" \
  -d '{
    "customerId": "le_cus_2rj4l7hmrrrcv",
    "accountId": "sa_group_2rj4l7hmrrrcv",
    "issueDate": "2026-10-01",
    "dueDate": "2026-10-31",
    "timezone": "America/New_York",
    "lineItems": [
      {
        "name": "Consulting",
        "quantity": 10,
        "unitAmount": { "amount": 15000, "currency": "USD" }
      }
    ]
  }'
```

Payments settle into the account you choose. Bank transfer is always offered;
list other `paymentMethods` to let the customer pay by card, ACH debit or
crypto from the payment page as well.

## Schedule or send

Add a `scheduledSendDate` to create the invoice as `scheduled` instead.
Slash emails it at 9:00 on that day in the invoice's timezone, and until then
you can edit it freely. To send it early, use
[Send an invoice now](/api-reference/invoices/send). To drop it,
[void it](/docs/v2/invoices/collecting-payment#void-an-invoice).

## Edit an invoice

[Update an invoice](/api-reference/invoices/update) while it's `scheduled` or
`unpaid`, sending only what changes. Each edit renders a new PDF and refreshes
the billing details from the customer. On a sent invoice, changing the dates,
total or copied emails sends the customer the updated invoice and restarts its
[reminders](#reminders).

Once an invoice has a payment it can't be edited. Void it and issue a new
one.

## Reminders

While an invoice is `unpaid` or `partially_paid`, Slash emails the customer
reminders: three days before the due date (when the invoice gives more than
four days to pay), on the due date, and one, seven and thirty days after it.
They stop once the invoice is paid or voided.

[Send a payment reminder](/api-reference/invoices/send-reminder) emails one
now, at most once a day per invoice.

## Catalog items

Save the products and services you bill often with
[Create a catalog item](/api-reference/invoices/catalog-items/create), and set
a line item's `catalogItemId` to record which item it came from. The line item
still carries its own name and price, so editing or archiving the item never
changes invoices already issued.

## Invoice settings

[Invoice settings](/api-reference/invoices/settings/retrieve) hold who
invoices are from, the defaults the Slash dashboard fills in, the logo and
colors on the PDF and payment page, and the next invoice number. Until you
save them, they come from your business details.

To add a logo, [upload](/api-reference/documents/upload) a PNG or JPEG with
purpose `invoice_logo` and pass its id as `logoDocumentId` to
[Update invoice settings](/api-reference/invoices/settings/update).


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