---
title: "Username & Password Rules"
description: "The rules for setting a username."
url: https://help.flow-insight.com/en/articles/363-username-and-password-rules
collection: "Account & Settings"
updated: 2026-08-06
language: en
alternates: [ja]
---

# Username & Password Rules

The rules for setting a username.

For security reasons, we've set the following rules.

## Username

### Basic Requirements

-   Half-width (single-byte) characters
    
-   3–30 characters long
    

### Allowed Characters

-   Uppercase: A–Z
    
-   Lowercase: a–z
    
-   Numbers: 0-9
    
-   Symbols: "\_", "-", "."
    

### Notes

-   "\_", "-", and "." cannot be the first character of your username.
    
-   "\_", "-", and "." cannot be the last character of your username.
    

## Password

### Basic Requirements

-   At least 8 characters, including uppercase, lowercase, numbers, and symbols
    
-   Half-width (single-byte) characters
    

### Allowed Characters

-   Uppercase: A–Z
    
-   Lowercase: a–z
    
-   Numbers: 0-9
    
-   Symbols: ~\`!@#$%^&\*()\_-+={\[}\]|\\:;"'<,>.?/
    

If you have any questions or concerns, please contact us via chat on the Flow site/app, or at [support@flow-solutions.com](mailto:support@flow-solutions.com).