# Login hint

You can pre-fill the User ID (national identity number) for the BankID session.

The `login_hint` is always prefixed with a `:`:

```
:07025312345
```

There are two ways to send a User ID to BankID:

- As a `login_hint` parameter in the backchannel [Pushed Authorization Request](https://docs.stoe.no/bankid-oidc-provider/api/par.md).
- As a `login_hint` claim in an [encrypted request object](https://docs.stoe.no/bankid-oidc-provider/core-concepts/encrypted-request-object.md) in the [Authorization Request](https://docs.stoe.no/bankid-oidc-provider/api/authorize.md).

> **A hint is just an hint - not a fact**
>
> When pre-filling the User ID for an end user, the resulting authentication may specify **a different end user**.

> **No longer use login_hint=BIS or login_hint=BID**
>
> Previous versions of BankID allowed the use of login_hint to select desired Identity Provider and Level of Assurance.
>
> This is _no longer recommended_ as `acr_values` should be used for this purpose. Read more [here](https://docs.stoe.no/bankid-oidc-provider/core-concepts/identity-providers.md).