---
title: "RapidIdentity SMS Phone Number Formatting"
slug: "phone-number-formatting-for-sms"
description: "This is how RapidIdentity handles phone numbers used for SMS Authentication."
tags: ["RapidIdentity ", "SMS", "Authentication"]
updated: 2022-05-11T13:37:31Z
published: 2022-05-11T13:37:31Z
canonical: "help.rapididentity.com/phone-number-formatting-for-sms"
---

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

# Phone Number Formatting for SMS

## Configuring a Phone Number for SMS Authentication

The SMS function assumes the mobile number is stored in the format **[areacode][number]** and follows these basic rules:

- If the mobile number starts with a **+**, nothing will be added to it when dialing.
- If the mobile number does **not** start with a **+**, the **dialPrefix** will be prepended to the number before dialing. The dialPrefix must be defined for anything to be prepended to the number.
  - The dial prefix must include a + followed by 0-4 digits. For the majority of users, this will include the country code. If the user's number does not match the country code of the dialPrefix, it should be stored with **+[countrycode][areacode][number]**.
- All other non-numeric characters will be stripped per SMS requirements.

**Example**:

```
Dial prefix: +1  
Stored mobile number: +1-(123)-456-7890
Sent to mobile number: +11234567890

Dial prefix: +1
Stored mobile number: (123)-456-7890
Sent to mobile number: +11234567890

Dial prefix: +1
Stored mobile number: +44-(123)-456-7890
Sent to mobile number: +441234567890

No Dial prefix
Stored mobile number: 1-(123)-456-7890
Error, not sent... missing '+'
```