# How Invoices Work

Invoices let you request payment from buyers for goods or services. Each invoice includes a unique invoice number, itemized details, a due date, and a hosted payment page where buyers can complete payment. You can create, send, and manage invoices directly from the Finix Dashboard.

## Invoices vs. Payment Links

Both Invoices and Payment Links are low-code/no-code solutions for accepting payments. However, there are some key differences between the two:

- **Invoices** are tied to a specific buyer and include a unique invoice number, itemized details, and a due date. They are formal documents suitable for business transactions and tax records. Invoices can be paid in full or in partial payments.
- [Payment Links](/low-code-no-code/payment-links/payment-links) are accessible to anyone with the link and do not support partial payments.


## Invoice Lifecycle

When you create an invoice, Finix generates:

- A unique invoice number for tracking and reference.
- A link that directs buyers to a hosted payment page.
- A PDF of the invoice that can be downloaded or sent to buyers.


The typical invoice lifecycle follows these steps:

1. **Create**: You create an invoice on the Dashboard with buyer details, line items, and a due date.
2. **Send**: You send the invoice to the buyer via email or share the payment page link directly.
3. **Pay**: The buyer clicks the link and completes the payment on the hosted payment page.
4. **Complete**: The invoice is marked as **Paid** and a receipt can be sent to the buyer.


## Invoice States

Invoices transition through different states based on payment activity. You can view and filter invoices by state on the Dashboard.

| State | Description |
|  --- | --- |
| **Open** | The invoice has been created and is awaiting payment. No payments have been received yet. |
| **Partially Paid** | A payment has been made, but the full amount has not been collected. Only available when partial payments are enabled. |
| **Paid** | The invoice has been paid in full. No further action is required. |
| **Void** | The invoice has been canceled and is no longer payable. Use this when an invoice was created in error or is no longer needed. |
| **Uncollectible** | The invoice is unlikely to be paid (e.g., past due and unrecoverable). |


### Open

An invoice starts in the **Open** state after it's created. The buyer can access the payment page and pay the invoice at any time before the due date. If the due date passes without payment, the invoice is marked as past due but remains in the **Open** state.

### Partially Paid

When [partial payments are enabled](/low-code-no-code/invoices/accepting-partial-payments), buyers can pay a portion of the invoice amount. The invoice moves to **Partially Paid** and displays the remaining balance. The buyer can continue making payments until the invoice is fully paid.

### Paid

An invoice moves to **Paid** when the full amount has been collected. This can happen in a single payment or through multiple partial payments. Once paid, the invoice is complete and no further payments are accepted.

### Void

You can void an invoice that was created in error or is no longer needed. Voiding an invoice cancels it and prevents any future payments. Voided invoices remain visible on the Dashboard for record-keeping but are clearly marked as canceled.

To mark an invoice as void:

1. From the Finix Dashboard, click **Payment Tools** > **Invoices**.
2. Click the invoice you want to mark as uncollectible.
3. Click the **...** icon and select **Void**.
  - A banner appears at the top of the invoice page confirming the action.


Voided Invoice
Voiding Invoices
You cannot void an invoice that has already received a payment. If partial payments have been made, you'll need to process refunds separately.

### Uncollectible

Mark an invoice as **Uncollectible** when you've determined it won't be paid. This is typically used for invoices that are significantly past due and all collection attempts have failed. Marking an invoice as uncollectible is a bookkeeping action that helps you track invoices that unlikly to be paid.

To mark an invoice as uncollectible,

1. From the Finix Dashboard, click **Payment Tools** > **Invoices**.
2. Click the invoice you want to mark as uncollectible.
3. Click the **...** icon and select **Uncollectible**.
  - A banner appears at the top of the invoice page confirming the action.


Uncollectible Invoice
## State Transitions

### Payment Flow

Invoices move through these states as payments are received.


```mermaid
stateDiagram-v2
    direction TB

    [*] --> Open: Create Invoice

    Open --> PartiallyPaid
    Open --> Paid

    PartiallyPaid --> Paid

    Paid --> [*]
```

### Cancellation Flow with No Partial Payments

You can [void](#void) or [mark an invoice as uncollectible](#uncollectible) to close it without full payment.


```mermaid
stateDiagram-v2
    direction TB

    [*] --> Open: Create Invoice

    %% Main flows from Open
    Open --> Void: Cancel
    Open --> Uncollectible

    %% End states
    Void --> [*]
    Uncollectible --> [*]
```

### Cancellation Flow with Partial Payments

If an invoice has received partial payments, you can still void it or mark it as uncollectible. Any payments already collected must be refunded separately.


```mermaid
stateDiagram-v2
    direction TB

    [*] --> Open
    Open : Create Invoice

    %% Main flows from Open
    Open --> PartiallyPaid

    %% From Partially Paid, two possible outcomes
    PartiallyPaid --> Void
    PartiallyPaid --> Uncollectible

    %% Refund separately as transition text before closing
    Void --> [*] : Refund Separately
    Uncollectible --> [*] : Refund Separately
```

## Payment Methods

You can allow buyers to pay with credit/debit cards, Apple Pay, and Google Pay. For more information, see [Payment Methods for Invoices](/low-code-no-code/invoices/payment-methods-for-invoices).

## Due Dates and Expiration

### Due Date

The **due date** is when payment is expected from the buyer. You set the due date when creating an invoice. After the due date passes:

- The invoice remains **Open** and payable.
- The invoice is flagged as **past due** on the Dashboard.
- Buyers can still access the payment page and complete payment.


### Link Expiration

The payment page link has a separate expiration date from the due date. By default, payment page links expire 3 years after the invoice is created. After the link expires:

- Buyers can no longer access the hosted payment page.
- The invoice remains on the Dashboard but cannot be paid through the original link.


## Key Invoice Settings

When creating an invoice on the Dashboard, you can configure the following settings:

| Setting | Description |
|  --- | --- |
| **Invoice Number** | A unique identifier for the invoice. Finix auto-generates this, but you can customize it. |
| **Due Date** | The date by which payment is expected from the buyer. |
| **Buyer** | The identity associated with the invoice. Required for tracking and communication. |
| **Line Items** | Individual items or services being billed, including descriptions, quantities, and amounts. |
| **Partial Payments** | When enabled, buyers can pay a portion of the invoice amount. See [Accepting Partial Payments](/low-code-no-code/invoices/accepting-partial-payments). |
| **Branding** | Customize the invoice and payment page with your logo and brand colors. See [Customize Branding](/low-code-no-code/invoices/customize-branding). |
| **Receipt** | When enabled, a receipt is automatically sent to the buyer after payment. |


## Related Guides

- [Invoices Quickstart](/low-code-no-code/invoices/invoices-quickstart) - Create your first invoice.
- [Accepting Partial Payments](/low-code-no-code/invoices/accepting-partial-payments) - Enable installment payments.
- [Sharing Invoices](/low-code-no-code/invoices/sharing-invoices) - Share
- [Customize Branding](/low-code-no-code/invoices/customize-branding) - Add your logo and brand colors.