# Ultralight signature level
You can use the Ultralight signing level when lighter authentication is sufficient and you want to maximise the speed and convenience of the signing process.
The Ultralight signature meets the requirements of a simple electronic signature (SES) under the eIDAS Regulation.
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Please note that with this level, the signer’s identity is verified only through a link sent to their email or mobile phone. Therefore, the Ultralight signature is **not suitable** for situations involving documents of significant financial value or where there is an elevated risk that the signer may later dispute the authenticity of the signature.
{% endhint %}
### **Choosing the delivery method**
When you select the Ultralight signing level, you must specify how the signing invitation will be delivered.\
By default, the delivery method is set to **Phone**. However, you can switch it to **Email** or choose **both**. In this case, the recipient will receive the invitation link by both SMS and email and can choose which one to use for signing.
### **Entering the phone number**
If you choose **Phone** as the delivery method, you must enter the recipient's mobile phone number in international format. The number should be entered after the country code, without the leading zero (e.g., +358 40 123 456).
The recipient’s default country code is based on your organisation account's country settings, but you can change it if needed.
{% hint style="warning" %}
**Sending SMS messages is a paid add-on service.**
Usage is charged per message according to the current [price list](https://signspace.vastuugroup.fi/en/pricing).
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