@dnb/eufemia/docs/uilib/extensions/forms/feature-fields/BankAccountNumber.md

DNB Eufemia Design System UI Library

---
title: 'Field.BankAccountNumber'
description: '`Field.BankAccountNumber` is a wrapper component for the input of strings, with user experience tailored for bank account number values.'
version: 10.104.0
generatedAt: 2026-04-17T18:46:12.720Z
checksum: 090b7d977ba4be5e2c4c04d199a30a4048416c59f443a56985df2f80629d9c40
---

# Field.BankAccountNumber

## Import

```tsx
import { Field } from '@dnb/eufemia/extensions/forms'
render(<Field.BankAccountNumber />)
```

## Description

`Field.BankAccountNumber` is a wrapper component for [string input](/uilib/extensions/forms/base-fields/String), with user experience tailored for bank account values.

This field is meant for Norwegian bank account numbers and therefore takes an 11-digit string as a value. A Norwegian bank account number can have a leading zero, which is why this value is a string and not a number. In addition, we validate `0000 00 00000` as invalid.
More information can be found at [Wikipedia](https://no.wikipedia.org/wiki/Kontonummer).

There is a corresponding [Value.BankAccountNumber](/uilib/extensions/forms/Value/BankAccountNumber) component.

## Relevant links

- [Source code](https://github.com/dnbexperience/eufemia/tree/main/packages/dnb-eufemia/src/extensions/forms/Field/BankAccountNumber)
- [Docs code](https://github.com/dnbexperience/eufemia/tree/main/packages/dnb-design-system-portal/src/docs/uilib/extensions/forms/feature-fields/BankAccountNumber)

## Validators

### Internal validators exposed

`Field.BankAccountNumber` exposes the `bankAccountNumberValidator` validator through its `onChangeValidator` and `onBlurValidator` properties. Take a look at [this demo](/uilib/extensions/forms/feature-fields/BankAccountNumber/demos/#extend-validation-with-custom-validation-function).
The `bankAccountNumberValidator` validator validates whether the bank account number provided is a [Norwegian bank account number](https://no.wikipedia.org/wiki/Kontonummer) or not.

### Extending validators

Use the `validators` parameter to keep the default checks and add your own custom rule. Import `BankAccountNumberValidator` to type your `onBlurValidator` and get the typed `validators` object.

```tsx
import { Field } from '@dnb/eufemia/extensions/forms'
import type { BankAccountNumberValidator } from '@dnb/eufemia/extensions/forms/Field/BankAccountNumber'

const myValidator: BankAccountNumberValidator = (
  value,
  { validators }
) => {
  const { bankAccountNumberValidator } = validators ?? {}
  const prefixChecker = (value: string) => {
    if (value && value[0] !== '1') {
      return new Error('Account number must start with 1')
    }
  }

  // Keep the built-in validator and add a custom prefix rule.
  return [bankAccountNumberValidator, prefixChecker]
}

render(<Field.BankAccountNumber onBlurValidator={myValidator} />)
```

## Demos

### Empty

```tsx
render(
  <Field.BankAccountNumber
    onChange={(value) => console.log('onChange', value)}
  />
)
```

### Omit mask

```tsx
render(
  <Field.BankAccountNumber
    onChange={(value) => console.log('onChange', value)}
    omitMask
  />
)
```

### Placeholder

```tsx
render(
  <Field.BankAccountNumber
    placeholder="Enter 11 digits..."
    onChange={(value) => console.log('onChange', value)}
  />
)
```

### Label

```tsx
render(
  <Field.BankAccountNumber
    label="Label text"
    onChange={(value) => console.log('onChange', value)}
  />
)
```

### Label and value

```tsx
render(
  <Field.BankAccountNumber
    label="Label text"
    value="20001234567"
    onChange={(value) => console.log('onChange', value)}
  />
)
```

### With help

```tsx
render(
  <Field.BankAccountNumber
    label="Label text"
    value="20001234567"
    help={{
      title: 'Help is available',
      content:
        'The real point is that we all need help somewhere along life’s path whether we think we will or not. And, if you are the one giving and helping, just remember this: no matter what happens later, you will always be secure in the fact knowing that you have remained strong and true to assist those that need your help.',
    }}
    onChange={(value) => console.log('onChange', value)}
  />
)
```

### Disabled

```tsx
render(
  <Field.BankAccountNumber
    value="20001234567"
    label="Label text"
    onChange={(value) => console.log('onChange', value)}
    disabled
  />
)
```

### Error

```tsx
render(
  <Field.BankAccountNumber
    value="007"
    label="Label text"
    onChange={(value) => console.log('onChange', value)}
    error={new Error('This is what is wrong...')}
  />
)
```

### Validation - Required

```tsx
render(
  <Field.BankAccountNumber
    value="20001234567"
    label="Label text"
    onChange={(value) => console.log('onChange', value)}
    required
  />
)
```

### Extend validation with custom validation function

You can [extend the existing validation](/uilib/extensions/forms/create-component/useFieldProps/info/#validators) (`bankAccountNumberValidator`) with your own validation function.

```tsx
const firstDigitIs1Validator = (value: string) => {
  if (value.substring(0, 1) !== '1') {
    return new Error('First digit is not 1')
  }
}

// Keep the built-in validator and add your own checks.
// Keep the built-in validator and add your own checks.
const myValidator: BankAccountNumberValidator = (
  value,
  { validators }
) => {
  const { bankAccountNumberValidator } = validators ?? {}
  return [bankAccountNumberValidator, firstDigitIs1Validator]
}
render(
  <Field.BankAccountNumber
    required
    value="65845125621"
    onBlurValidator={myValidator}
    validateInitially
  />
)
```

## Properties

### Field-specific properties

```json
{
  "props": {
    "multiline": {
      "doc": "True to be able to write in multiple lines (switching from input-element to textarea-element).",
      "type": "boolean",
      "status": "optional"
    },
    "leftIcon": {
      "doc": "For icon at the left side of the text input. Only one of `leftIcon` or `rightIcon` can be used at the same time.",
      "type": "string",
      "status": "optional"
    },
    "rightIcon": {
      "doc": "For icon at the right side of the text input. Only one of `leftIcon` or `rightIcon` can be used at the same time.",
      "type": "string",
      "status": "optional"
    },
    "capitalize": {
      "doc": "When set to true, it will capitalize the first letter of every word, transforming the rest to lower case.",
      "type": "boolean",
      "status": "optional"
    },
    "trim": {
      "doc": "When true, it will trim leading and trailing whitespaces on blur, triggering `onChange` if the value changes.",
      "type": "boolean",
      "status": "optional"
    },
    "inputMode": {
      "doc": "Define an [inputmode](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/inputmode).",
      "type": "string",
      "status": "optional"
    },
    "autoComplete": {
      "doc": "For HTML [autocomplete](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/autocomplete) attributes.",
      "type": ["on", "string"],
      "status": "optional"
    },
    "minLength": {
      "doc": "Validation for minimum length of the text (number of characters).",
      "type": "number",
      "status": "optional"
    },
    "maxLength": {
      "doc": "Validation for maximum length of the text (number of characters).",
      "type": "number",
      "status": "optional"
    },
    "pattern": {
      "doc": "Validation based on regex pattern.",
      "type": "string",
      "status": "optional"
    },
    "width": {
      "doc": "`false` for no width (use browser default), `small`, `medium` or `large` for predefined standard widths, `stretch` to fill available width.",
      "type": ["string", "false"],
      "status": "optional"
    },
    "size": {
      "doc": "The sizes you can choose is `default` (2rem), `medium` (2.5rem) and `large` (3rem) are supported component sizes. Defaults to `default` / `null`. Also, if you define a number like `size={2}` then it will be forwarded as the input element attribute. Consider rather setting field sizes with [Form.Appearance](/uilib/extensions/forms/Form/Appearance/).",
      "type": ["string", "number"],
      "status": "optional"
    },
    "align": {
      "doc": "Defines the text alignment of the input. Can be `left`, `right` or `center`. Defaults to `left`.",
      "type": "string",
      "status": "optional"
    },
    "selectall": {
      "doc": "If set to `true`, then the whole input value gets selected on the entry focus. A second click will place the cursor on the wanted position.",
      "type": "boolean",
      "status": "optional"
    },
    "clear": {
      "doc": "If set to `true`, then a clear button will be shown which lets the user clear any given input value.",
      "type": "boolean",
      "status": "optional"
    },
    "keepPlaceholder": {
      "doc": "Set to `true` in case the `placeholder` has to be kept during focus. By default, the placeholder disappears on focus.",
      "type": "boolean",
      "status": "optional"
    },
    "rows": {
      "doc": "To be used together with `multiline`. Set how many rows of text can be shown by default. Defaults to `2`.",
      "type": "number",
      "status": "optional"
    },
    "autoresizeMaxRows": {
      "doc": "To be used together with `multiline`. Set how many rows of text can be shown at max. Defaults to `6`.",
      "type": "number",
      "status": "optional"
    },
    "characterCounter": {
      "doc": "To be used together with `multiline`. Use a number to define the displayed max length e.g. `40` or `{ max: 40, variant: 'down' }`.",
      "type": ["number", "object"],
      "status": "optional"
    },
    "autoresize": {
      "doc": "To be used together with `multiline`. Set true to expand when writing longer texts. Defaults to `true`.",
      "type": "boolean",
      "status": "optional"
    },
    "inputClassName": {
      "doc": "Class name set on the <input> DOM element.",
      "type": "string",
      "status": "optional"
    },
    "innerRef": {
      "doc": "By providing a React.Ref we can get the internally used input element (DOM).",
      "type": "React.RefObject",
      "status": "optional"
    },
    "submitElement": {
      "doc": "Accepts a React element which will show up like the \"submit button\" would do on type=\"search\".",
      "type": "React.Element",
      "status": "optional"
    },
    "validate": {
      "doc": "Using this prop you can disable the default validation.",
      "type": "boolean",
      "status": "optional"
    },
    "onBlurValidator": {
      "doc": "Custom validator function that is triggered when the user leaves a field (e.g., blurring a text input or closing a dropdown). The function can be either asynchronous or synchronous. The first parameter is the value, and the second parameter returns an object containing { errorMessages, connectWithPath, validators }. Defaults to bank account number validation, using `bankAccountNumberValidator`. Can be disabled using `false`.",
      "type": "function",
      "status": "optional"
    }
  }
}
```

### General properties

```json
{
  "props": {
    "value": {
      "doc": "Source data value for the field. Will take precedence over the path value given in the data context.",
      "type": "{valueType}",
      "status": "optional"
    },
    "defaultValue": {
      "doc": "Default source data value for the field. Will not take precedence over the path value given in the data context.",
      "type": "{valueType}",
      "status": "optional"
    },
    "path": {
      "doc": "JSON Pointer for where the data for the field is located in the source dataset (when using Form.Handler or DataContext). The `path` will also be set as the `name` attribute for the [string](/uilib/extensions/forms/base-fields/String/)-field.",
      "type": "string",
      "status": "optional"
    },
    "info": {
      "doc": "Info message shown below / after the field by default. Use `statusPosition=\"above\"` to show status messages above the field. When provided as a function, the function will be called with the current value as argument. The second parameter is an object with `{ conditionally, getValueByPath, getFieldByPath }`. To show the message first after the user has interacted with the field, you can call and return `conditionally` function with a callback and with options: `conditionally(() => 'Your message', { showInitially: true })`",
      "type": ["React.Node", "Array<React.Node>", "function"],
      "status": "optional"
    },
    "warning": {
      "doc": "Warning message shown below / after the field by default. Use `statusPosition=\"above\"` to show status messages above the field. When provided as a function, the function will be called with the current value as argument. The second parameter is an object with `{ conditionally, getValueByPath, getFieldByPath }`. To show the message first after the user has interacted with the field, you can call and return `conditionally` function with a callback and with options: `conditionally(() => 'Your message', { showInitially: true })`",
      "type": ["React.Node", "Array<React.Node>", "function"],
      "status": "optional"
    },
    "error": {
      "doc": "Error message shown below / after the field. When provided as a function, the function will be called with the current value as argument. The second parameter is an object with `{ conditionally, getValueByPath, getFieldByPath }`. To show the message first after the user has interacted with the field, you can call and return `conditionally` function with a callback and with options: `conditionally(() => 'Your message', { showInitially: true })`",
      "type": [
        "Error",
        "FormError",
        "Array<Error | FormError>",
        "function"
      ],
      "status": "optional"
    },
    "disabled": {
      "doc": "Set `true` to show the field but without the possibility of changing the value.",
      "type": "boolean",
      "status": "optional"
    },
    "emptyValue": {
      "doc": "The value to use (in `onChange` events etc) when emptying the field. Makes it possible for instance to provide `undefined` instead of an empty string when clearing the content of a text input.",
      "type": ["{valueType}", "undefined"],
      "status": "optional"
    },
    "required": {
      "doc": "When set to `true`, the field will give an error if the value fails the required validation. When set to `false`, the field will not be required, but will add a \"(optional)\" suffix to the label.",
      "type": "boolean",
      "status": "optional"
    },
    "labelSuffix": {
      "doc": "Will append an additional text to the label, like \"(optional)\". When using `inheritLabel`, the suffix will not be inherited. NB: The visual appearance of the `labelSuffix` may change in the future.",
      "type": "React.Node",
      "status": "optional"
    },
    "schema": {
      "doc": "Custom JSON Schema for validating the value.",
      "type": "object",
      "status": "optional"
    },
    "validateInitially": {
      "doc": "Set to `true` to show validation based errors initially (from given value-prop or source data) before the user interacts with the field.",
      "type": "boolean",
      "status": "optional"
    },
    "validateUnchanged": {
      "doc": "Set to `true` to show validation based errors when the field is touched (like focusing a field and blurring) without having changed the value. Since the user did not introduce a new error, this will apply when the value was initially invalid based on validation.",
      "type": "boolean",
      "status": "optional"
    },
    "validateContinuously": {
      "doc": "Set to `true` to show validation based errors continuously while writing, not just when blurring the field.",
      "type": "boolean",
      "status": "optional"
    },
    "errorMessages": {
      "doc": "Custom error messages for each type of error, overriding default messages. The messages can be a React.ReactNode or a string.",
      "type": "object",
      "status": "optional"
    },
    "onChangeValidator": {
      "doc": "Custom validator function where you can return `undefined`, `Error`, `FormError` or an Array with either several other validators or several `Error` or `FormError`. It is triggered on every change done by the user. The function can be either asynchronous or synchronous. The first parameter is the value, and the second parameter returns an object containing { errorMessages, connectWithPath, validators }.",
      "type": "function",
      "status": "optional"
    },
    "onBlurValidator": {
      "doc": "Custom validator function where you can return `undefined`, `Error`, `FormError` or an Array with either several other validators or several `Error` or `FormError`. It is triggered when the user leaves a field (e.g., blurring a text input or closing a dropdown). The function can be either asynchronous or synchronous. The first parameter is the value, and the second parameter returns an object containing { errorMessages, connectWithPath, validators }.",
      "type": "function",
      "status": "optional"
    },
    "transformIn": {
      "doc": "Transforms the `value` before its displayed in the field (e.g. input).",
      "type": "function",
      "status": "optional"
    },
    "transformOut": {
      "doc": "Transforms the value before it gets forwarded to the form data object (context) or returned as the `onChange` value parameter. The first parameter is the internal value. Some fields do support a second parameter, like the SelectCountry, where the country object is given.",
      "type": "function",
      "status": "optional"
    },
    "label": {
      "doc": "Label text displayed above the field. Most fields already have a default label, so check the field translations for an existing label entry. Only set `label` when you need to override the default.",
      "type": "string",
      "status": "optional"
    },
    "labelDescription": {
      "doc": "A more discreet text displayed beside the label (i.e for \"(optional)\").",
      "type": "string",
      "status": "optional"
    },
    "labelDescriptionInline": {
      "doc": "If true, the `labelDescription` will be displayed on the same line as the label.",
      "type": "boolean",
      "status": "optional"
    },
    "labelSrOnly": {
      "doc": "Use `true` to make the label only readable by screen readers.",
      "type": "boolean",
      "status": "optional"
    },
    "labelSize": {
      "doc": "Define the font-size of the label based on the [font-size](/uilib/typography/font-size/) table.",
      "type": ["medium", "large"],
      "status": "optional"
    },
    "help": {
      "doc": "Provide help content for the field using `title` and `content` as a string or React.Node. Additionally, you can set `open` to `true` to display the inline help, set the `breakout` property to `false` to disable the breakout of the inline help content, set `outset` to `false` to display the help text inline (inset) instead of the default outset behavior, or use `renderAs` set to `dialog` to render the content in a [Dialog](/uilib/components/dialog/) (recommended for larger amounts of content).",
      "type": "object",
      "status": "optional"
    },
    "hideHelpButton": {
      "doc": "Set `true` when you render the inline help button outside the label (e.g. inside a checkbox suffix) so FieldBlock skips drawing the default label help button.",
      "type": "boolean",
      "status": "optional"
    },
    "statusPosition": {
      "doc": "Controls where status messages (`error`, `warning`, `info`) are visually shown. Use `below` (default) or `above`.",
      "type": ["\"below\"", "\"above\""],
      "status": "optional"
    },
    "layout": {
      "doc": "Layout for the label and input. Can be `horizontal` or `vertical`.",
      "type": "string",
      "status": "optional"
    },
    "layoutOptions": {
      "doc": "Use this to set additional options for the `horizontal` layout. E.g. `{ width: \"medium\" }`. You can also use a custom width `{number}rem`. Instead of a width, you can use a min/max width. E.g. `{ minWidth: \"6rem\", maxWidth: \"12rem\" }`.",
      "type": "object",
      "status": "optional"
    },
    "width": {
      "doc": "Will set the width for the whole block. Use `small`, `medium`, `large` for predefined standard widths. You can also set a custom width `{number}rem` or use `stretch` or `false`.",
      "type": ["string", "false"],
      "status": "optional"
    },
    "contentWidth": {
      "doc": "Will set the width for its contents. Use `small`, `medium`, `large` for predefined standard widths. You can also set a custom width `{number}rem` or use `stretch` or `false`.",
      "type": ["string", "false"],
      "status": "optional"
    },
    "[Space](/uilib/layout/space/properties)": {
      "doc": "Spacing properties like `top` or `bottom` are supported.",
      "type": ["string", "object"],
      "status": "optional"
    }
  },
  "omit": ["onBlurValidator"]
}
```

## Translations

```json
{
  "locales": ["da-DK", "en-GB", "nb-NO", "sv-SE"],
  "entries": {
    "BankAccountNumber.errorBankAccountNumber": {
      "nb-NO": "Ugyldig kontonummer.",
      "en-GB": "Invalid account number.",
      "sv-SE": "Ogiltigt kontonummer.",
      "da-DK": "Ugyldigt kontonummer."
    },
    "BankAccountNumber.errorBankAccountNumberLength": {
      "nb-NO": "Du må skrive inn et gyldig kontonummer med 11 siffer.",
      "en-GB": "You must enter a valid account number with 11 digits.",
      "sv-SE": "Du måste ange ett giltigt kontonummer med 11 siffror.",
      "da-DK": "Du skal indtaste et gyldigt kontonummer med 11 cifre."
    },
    "BankAccountNumber.errorRequired": {
      "nb-NO": "Du må fylle inn et kontonummer.",
      "en-GB": "You must enter an account number.",
      "sv-SE": "Du måste fylla i ett kontonummer.",
      "da-DK": "Du skal udfylde et kontonummer."
    },
    "BankAccountNumber.label": {
      "nb-NO": "Bankkonto",
      "en-GB": "Bank account",
      "sv-SE": "Bankkonto",
      "da-DK": "Bankkonto"
    },
    "Field.errorPattern": {
      "nb-NO": "Du må skrive inn en gyldig verdi.",
      "en-GB": "You must enter a valid value.",
      "sv-SE": "Du måste ange ett giltigt värde.",
      "da-DK": "Du skal indtaste en gyldig værdi."
    },
    "Field.errorRequired": {
      "nb-NO": "Dette feltet må fylles ut.",
      "en-GB": "This field is required.",
      "sv-SE": "Detta fält måste fyllas i.",
      "da-DK": "Dette felt skal udfyldes."
    },
    "Field.errorSummary": {
      "nb-NO": "Feil som må rettes:",
      "en-GB": "Please correct the following errors:",
      "sv-SE": "Fel som måste åtgärdas:",
      "da-DK": "Felter der skal rettes:"
    },
    "Field.errorSummaryTitle": {
      "nb-NO": "Feil som må rettes",
      "en-GB": "Please correct the following errors",
      "sv-SE": "Fel som måste åtgärdas",
      "da-DK": "Felter der skal rettes"
    },
    "Field.optionalLabelSuffix": {
      "nb-NO": "(valgfritt)",
      "en-GB": "(optional)",
      "sv-SE": "(valfritt)",
      "da-DK": "(valgfrit)"
    },
    "Field.stateSummary": {
      "nb-NO": "Oppsummering:",
      "en-GB": "Summary:",
      "sv-SE": "Sammanfattning:",
      "da-DK": "Oversigt:"
    }
  }
}
```

## Events

```json
{
  "props": {
    "onChange": {
      "doc": "Will be called on value changes made by the user, with the new value as argument. When an `async` function is used, the corresponding [FieldBlock](/uilib/extensions/forms/create-component/FieldBlock/) will show an indicator on the field label. You can return `{ success: 'saved' } as const` to show a success symbol, or an error or an object with these keys `{ info: 'Info message', warning: 'Warning message', error: Error('My error') } as const`. The second parameter is an object that e.g. contains `props` (all given `Field.*` properties).",
      "type": "(value) => void",
      "status": "optional"
    },
    "onFocus": {
      "doc": "Will be called when the component gets into focus. Like clicking inside a text input or opening a dropdown. Called with active value as argument. The second parameter is an object that e.g. contains `props` (all given `Field.*` properties).",
      "type": "(value) => void",
      "status": "optional"
    },
    "onBlur": {
      "doc": "Will be called when the component stop being in focus. Like when going to next field, or closing a dropdown. Called with active value as argument. The second parameter is an object that e.g. contains `props` (all given `Field.*` properties).",
      "type": "(value) => void",
      "status": "optional"
    },
    "onStatusChange": {
      "doc": "Called whenever the status messages (info, warning or error) gets visible or changes. Receives the current `{ info, warning, error }` object.",
      "type": "({ info?, warning?, error? }: FieldStatus) => void",
      "status": "optional"
    }
  }
}
```