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

# Bank reference

> Full options, fields, and value reference for the bank element.

## Factory

```typescript theme={null}
overflow.bank(options?: BankElementOptions): BankElement
```

## Options

All keys are optional.

| Key            | Type                    | Default                  | Description                                                                                                          |
| -------------- | ----------------------- | ------------------------ | -------------------------------------------------------------------------------------------------------------------- |
| `mode.default` | `'plaid' \| 'manual'`   | `'plaid'`                | Which mode renders on mount when neither side is locked.                                                             |
| `mode.lockTo`  | `'plaid' \| 'manual'`   | none                     | Locks the shopper to one mode. The toggle button is hidden and programmatic mode switches are ignored.               |
| `disabled`     | `boolean`               | `false`                  | Locks the manual-mode inputs and the mode toggle. Does not fully suppress fast-signin; unmount if you need that.     |
| `readOnly`     | `boolean`               | `false`                  | Cascades to the three manual-mode text inputs. The account-type `<select>` ignores `readOnly` per browser semantics. |
| `id`           | `string`                | auto                     | DOM id on the host wrapper.                                                                                          |
| `ariaLabel`    | `string`                | none                     | Sets `aria-label` and `role="group"` on the host wrapper when supplied.                                              |
| `locale`       | `string`                | Overflow instance locale | BCP-47 locale for labels.                                                                                            |
| `fieldLayout`  | `'stacked' \| 'inline'` | `'stacked'`              | Layout for the manual-mode inputs.                                                                                   |
| `fields`       | see below               | `{}`                     | Per-input customization.                                                                                             |

`bank` does not accept a top-level `required` or `validate`. Both modes are implicitly required. See [`required`](/payment-elements/options/required) for the exact behavior.

## `fields` (manual mode)

### `accountType`

| Key         | Type      | Default          |
| ----------- | --------- | ---------------- |
| `label`     | `string`  | `'Account type'` |
| `hidden`    | `boolean` | `false`          |
| `disabled`  | `boolean` | inherits         |
| `id`        | `string`  | auto             |
| `ariaLabel` | `string`  | none             |

When hidden, the validator skips the account-type check. `placeholder` is not supported on the `<select>`.

### `routingNumber`, `accountNumber`, `confirmAccountNumber`

Each accepts:

| Key           | Type      | Default                |
| ------------- | --------- | ---------------------- |
| `label`       | `string`  | field-specific default |
| `placeholder` | `string`  | none                   |
| `disabled`    | `boolean` | inherits               |
| `autoFocus`   | `boolean` | `false`                |
| `id`          | `string`  | auto                   |
| `ariaLabel`   | `string`  | none                   |

`hidden` is not supported on these three fields: they are interdependent and cannot be individually collapsed.

## Value

The bank element emits a discriminated union on `onSubmit` keyed by `mode`. Manual-mode payloads carry encrypted account credentials; fast-signin (Plaid) payloads carry a linked-account token.

```typescript theme={null}
type BankElementValue =
  | {
      mode: 'manual';
      bankAccountType: 'checking' | 'savings';
      encryptedBankAccountNumber: string;
      encryptedBankRoutingNumber: string;
    }
  | BankPlaidValue;

type BankPlaidValue = {
  mode: 'plaid';
  publicToken: string;
  accountId: string;
  institutionName: string;
  accountLast4: string;
  accountType?: 'checking' | 'savings';
};
```

Forward the full envelope to your server verbatim. Do not attempt to unpack the `encrypted*` fields on the manual branch; they are decrypted server-side by Overflow.

## `FieldError.field` values

`'accountType'`, `'routingNumber'`, `'accountNumber'`, `'confirmAccountNumber'`, `'bank'` (synthetic error when the shopper selects bank inside Checkout but never completes fast-signin).

## Events

Every element event is supported. See [Events overview](/payment-elements/events/overview).

## Methods

* `bank.mount(selector)`
* `bank.update(partialOptions)`
* `bank.submit()`
* `bank.unmount()`
* `bank.destroy()`
* `bank.on(event, handler)`