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

# Card Number Input

> Secure input for card numbers with automatic network detection.

## \<primer-input-card-number>

Secure, PCI-compliant input for card numbers. Automatically detects and displays card network (Visa, Mastercard, etc.) as user types.

## Quick Reference

| | |
| - | - |
| **Parent** | `<primer-card-form>` |
| **Properties** | `label`, `placeholder`, `aria-label` |
| **Features** | Network detection, auto-formatting |

***

## Examples

### Default

```html theme={"dark"}
<primer-card-form>
  <primer-input-card-number></primer-input-card-number>
</primer-card-form>
```

### Custom Labels

```html theme={"dark"}
<primer-input-card-number
  label="Credit Card Number"
  placeholder="Enter your card number"
  aria-label="Your credit card number"
></primer-input-card-number>
```

### No Placeholder

```html theme={"dark"}
<primer-input-card-number placeholder=""></primer-input-card-number>
```

### In Custom Layout

```html theme={"dark"}
<primer-card-form>
  <div slot="card-form-content">
    <primer-input-card-number></primer-input-card-number>
    <div style="display: flex; gap: 8px;">
      <primer-input-card-expiry></primer-input-card-expiry>
      <primer-input-cvv></primer-input-cvv>
    </div>
    <button type="submit">Pay</button>
  </div>
</primer-card-form>
```

***

## Properties

| Property | Attribute | Type | Default | Description |
| - | - | - | - | - |
| `label` | `label` | `string` | `"Card Number"` | Label text |
| `placeholder` | `placeholder` | `string` | `"4111 1111 1111 1111"` | Placeholder text |
| `ariaLabel` | `aria-label` | `string` | Value of `label` | Screen reader label |

Setting to empty string `""`:

* `label`: Reverts to default
* `placeholder`: Shows no placeholder
* `aria-label`: Uses `label` value

***

## Card Network Detection

Automatically detects:

| Network | Example Prefix |
| - | - |
| Visa | 4xxx |
| Mastercard | 5xxx |
| Amex | 34xx, 37xx |
| Discover | 6011 |

Displays network logo and adjusts formatting (e.g., Amex uses different spacing).

***

## Validation

Validates:

* Number length matches detected network (e.g., 16 for Visa, 15 for Amex)
* At least one digit entered

Errors display automatically on submit or blur.

***

## Events

`<primer-input-card-number>` does not emit its own events. Validation and submission are managed by the parent `<primer-card-form>`.

### Relevant Parent Events

| Event | Emitted by | How it affects this input |
| - | - | - |
| `primer:card-submit` | `<primer-card-form-submit>` or external dispatch | Triggers validation — if this input is invalid, an error message displays below it |
| `primer:card-error` | `<primer-card-form>` | Emitted when any card input fails validation — payload includes all validation errors |
| `primer:card-success` | `<primer-card-form>` | Emitted when the form submits successfully |

### Reacting to card validation errors

```javascript theme={"dark"}
const cardForm = document.querySelector('primer-card-form');

cardForm.addEventListener('primer:card-error', (event) => {
  const { errors } = event.detail;
  errors.forEach(err => console.log(err.field, err.message));
});
```

***

## CSS Properties

This component uses the shared [Input Styling Tokens](https://primer.io/docs/sdk/primer-checkout-web/styling-variables.md#input-styling-tokens).

### Layout

| Property | Description | Default |
| - | - | - |
| `--primer-space-small` | Gap between input and network icon | `8px` |

### Typography

| Property | Description | Default |
| - | - | - |
| `--primer-typography-body-large-size` | Input text size | `16px` |
| `--primer-typography-body-large-weight` | Input text weight | `400` |
| `--primer-typography-body-small-size` | Label text size | `12px` |

### Colors

| Property | Description |
| - | - |
| `--primer-color-text-primary` | Input text color |
| `--primer-color-text-placeholder` | Placeholder text color |
| `--primer-color-text-disabled` | Disabled text color |
| `--primer-color-text-negative` | Error message color |

### Border & Background

| Property | Description |
| - | - |
| `--primer-radius-small` | Input border radius |
| `--primer-color-border-outlined-default` | Default border |
| `--primer-color-border-outlined-focus` | Focus border |
| `--primer-color-border-outlined-error` | Error border |
| `--primer-color-background-outlined-default` | Default background |

### Animation

| Property | Description | Default |
| - | - | - |
| `--primer-animation-duration` | Transition duration | `200ms` |
| `--primer-animation-easing` | Transition easing | `cubic-bezier(0.44, 0, 0.4, 1)` |

***

## States

| State | Description | Visual Change |
| - | - | - |
| **Default** | Initial state | Standard border and background |
| **Hover** | Mouse over input | Border darkens slightly |
| **Focus** | Input is focused | Blue border, increased width |
| **Filled** | Valid card number entered | Network icon displayed |
| **Error** | Invalid input or validation failed | Red border, error message below |
| **Disabled** | Form or input disabled | Muted colors, no interaction |

***

## Usage Guidelines

### Do

* Place inside `<primer-card-form>`
* Use for card number collection only

### Don't

* Don't use `<primer-card-network-selector>` separately (internal component)
* Don't place outside card form context

***

## Content Guidelines

### Label

| Do | Don't |
| - | - |
| "Card number" | "Credit card number" (not all cards are credit) |
| Use sentence case | "CARD NUMBER" |

### Placeholder

| Do | Don't |
| - | - |
| `1234 1234 1234 1234` (formatted example) | "Enter your card number" (redundant with label) |
| Empty placeholder (clean look) | A partial number like `4111` |

### Error messages

| Do | Don't |
| - | - |
| "Enter a valid card number" | "Invalid" |
| "Card number is incomplete" | "Error in field" |

***

## See also

> [card] [primer-card-form](https://primer.io/docs/sdk/primer-checkout-web/components/primer-card-form/primer-card-form.md)
>
> Parent container

> [card] [primer-input-card-expiry](https://primer.io/docs/sdk/primer-checkout-web/components/primer-card-form/primer-input-card-expiry.md)
>
> Expiry input

> [card] [primer-input-cvv](https://primer.io/docs/sdk/primer-checkout-web/components/primer-card-form/primer-input-cvv.md)
>
> CVV input


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