> ## Documentation Index
> Fetch the complete documentation index at: https://docs.duitpos.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Sales Invoices
> Record what you sold, including returns, and see it reflected in stock and accounting immediately.
A **Sales Invoice** records a sale to a customer — submitting one decreases stock on hand and increases **Sales Income**. It also supports **returns**, where a customer brings something back and it's linked to the original invoice it's returning against.
## Sales Invoice Fields
| Field | Required | Description |
| -------------------- | --------------------------- | -------------------------------------------------------------------------------------- |
| **Party (Customer)** | Yes | Must be a party marked `Is Customer` — see [Parties](/retail/party) |
| **Location** | Yes | Which branch/location this sale happened at |
| **Posting Date** | Yes | The sale date |
| **Currency** | No | Defaults to your base currency; set to a foreign currency if this customer pays in one |
| **Is Return** | No | Turn on to record a return |
| **Return Against** | Required if Is Return is on | The original Sales Invoice this return relates to |
| **Items** | Yes (at least 1) | Product, quantity, rate, tax per line |
## Returns
To record a customer return, create a new Sales Invoice with `Is Return` turned on and `Return Against` set to the original invoice. The items on a return are entered as positive quantities (the system handles the sign internally) — submitting it adds the stock back and reverses the appropriate portion of Sales Income.
If you're also tracking stock on hand for a product, the invoice's line items show a quick "in stock: X" hint so you can catch an oversell before it happens, rather than only finding out when the server rejects it.
## Create a Sales Invoice
Under Retail — Sales & Payments.
Choose the Customer, Location, and Posting Date.
Product, quantity, and rate for each item sold.
Stock decreases, Sales Income increases, and the invoice is ready to be paid.
## Frequently Asked Questions
No — if a product's Stock Profile has `Is Sales Item` turned off, the system rejects any attempt to add it to a Sales Invoice. See [Stock Profile](/retail/stock-profile).
No — a Sales Invoice records the sale and what's owed; a separate [Payment](/retail/payments) records money actually received.
Automatically, using FIFO (first-in, first-out) costing from your actual purchase history — you don't enter a cost manually on a sale.
## Related
Collect payment for this invoice
Set up your customers
See stock drop after a sale
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