# Bad value X for attribute “href” on element “a”: Illegal character after “tel:”. “"” is not allowed.

> Canonical HTML version: https://rocketvalidator.com/html-validation/bad-value-x-for-attribute-href-on-element-a-illegal-character-after-tel-quote-is-not-allowed
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

This `tel:` link has a double quote (`"`) inside its `href` value, and `"` is not allowed in a URL.

The usual cause is quotes around the phone number instead of around the attribute value. In `<a href=tel:"555-0100">`, the value itself is unquoted, so the HTML parser keeps both quote marks as part of it and the URL becomes `tel:"555-0100"`. For the same tag, the validator also reports `“"” in an unquoted attribute value`. Writing `href='tel:"555-0100"'`, or using `&quot;` entities, gives the same result, because `&quot;` turns into a real `"` before the URL is checked.

For the number itself, [RFC 3966](https://www.rfc-editor.org/info/rfc3966/) allows digits, a leading `+`, and the visual separators `-`, `.`, `(` and `)`. Quote the whole attribute value and keep the number bare inside it. The link text can show the number in whatever format reads best. A value that holds two numbers has to become two links. `Tel:` with a capital T is fine, since scheme names are case-insensitive, though most pages write `tel:`.

## Invalid example

```html
<a href=tel:"+1-555-0100">Call us</a>
```

## Valid example

```html
<a href="tel:+1-555-0100">+1 555-0100</a>
```