# Inside an invoice

_How an invoice's window works: items, discount, note, status and the footer buttons._

> **💡 Tip**
>
> Use the invoice's **Send** button to deliver the charge straight to the customer's **WhatsApp** — the fastest way to get paid. And track the **overdue** ones with the status filter to cut down on default.

Almost everything in TecPet **generates an invoice**: an appointment, a counter sale, the purchase of a plan/package. They all live under **Billing**. Here we explain the invoice **from the inside** — what you see and do when you open it. (To track the list day to day, see [Track billing](/en/operacao/financeiro/cobrancas/).)

## Invoice types

By **Type**, an invoice can be:
- **Appointment** — generated by an appointment (linked to it);
- **Plan/Package** — for the purchase or use of a plan;
- **Standalone** — a charge created manually, with no appointment;
- **Voucher** — related to a credit/voucher.

The type influences what you can edit and the footer texts.

## Sell a product (standalone sale)

To sell a **product** or charge for something **without an appointment**, create a **standalone sale**:
1. Open the [customer profile](/en/operacao/clientes-e-pets/perfil-do-cliente/) and click **New sale** — the **New Invoice** window opens;
2. Under **Items**, click the **+**. In the **Type** field, choose **Product** (the list also has *Service*, *Voucher*, *Pickup & delivery* and *Other*);
3. Fill in the **Product name**, the **Value** (R$) and the **Quantity**, then click **Save**;
4. Repeat to add more items. If you like, write a **Note** and adjust the **Due date**;
5. Click **Pay** to get paid right away, or **Send** to deliver the charge via **WhatsApp**.

## Products and stock

TecPet **has no built-in product catalog or stock control** — the **Product name** is typed freely at the time of sale. **Stock** is only moved when the store uses an **ERP integration**: with **VHSYS**, for example, the invoice's product becomes a **Sales Order** and **reduces stock** there. See [What changes with the integration on](/en/configuracao/integracoes/o-que-muda-com-a-integracao/) and [VHSYS integration](/en/configuracao/integracoes/integracao-vhsys/).

A product is **always added at full price**: **Product** items **don't accept a discount** on the invoice. Any product discount is applied later, in the **ERP/POS**.

## Find the invoice (filters)

Under **Billing**, click **Filter search** to open the filters: **period** and **date by** (creation, due, payment); **status** (All, Paid, Open, Overdue, Cancelled, No value); and **type** (Appointment, Plan/Package, Standalone, Voucher). Click **Filter** to apply.

![Billing filters panel: period, date, status and type](https://help.tec.pet/_md-assets/faturas__filtros.png)

## Open an invoice

In the list, each invoice has **Operations** icons: WhatsApp, **$** (register payment) and the **document icon**, which **opens the invoice**. Click the document icon on the desired row.

![Billing list with the Operations icons in the last column](https://help.tec.pet/_md-assets/faturas__lista.png)

## Inside the invoice

The window shows, at the top, **Customer**, **Pet**, **Appointment** (when there is one), **Segment** and the **Pay** button. Below:
- **Items** — the services/products charged; **+** adds an item, the **pencil** edits the value/quantity and the **trash** removes it;
- **Discounts** — discounts applied (e.g. a combo discount); you can add/edit;
- **Note** — a free note on the invoice;
- **Subtotal** and, in the footer, **Total**, **Paid** and **To receive**, plus the **Due date** (editable) and the **Status** (Pending, Paid, Overdue…).

![Invoice window with items, discounts, note, totals and status](https://help.tec.pet/_md-assets/faturas__modal.png)

## The footer buttons

At the bottom of the window:
- **Pay** (at the top) — registers the invoice payment;
- **History** — all changes to the invoice;
- **Print** — generates the invoice for printing;
- **Send** — delivers the charge via **WhatsApp**;
- **Reverse** — undoes the payment (only on an **already-paid** invoice);
- **Close**.

> **⚠️ Heads up**
>
> The **Reverse** button is only available on **already-paid** invoices (it undoes the payment). And the invoice **type** changes what you can edit: **plan/package** invoices follow the plan's rules, unlike a **standalone** one.

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_feature: fatura-modal · atualizado em 2026-06-10 · fonte: https://help.tec.pet/en/operacao/financeiro/a-fatura-por-dentro/ — TecPet Central de Ajuda_