X (Twitter) username rules
X (Twitter) usernames are 4 to 15 characters long. Letters, numbers and underscores.
- No spaces, dots or hyphens.
- Names containing Twitter or Admin are refused.
Source: X (Twitter) help. Checked October 2026. Platforms change their rules; their help page is the final word.
A format check only. It does not say whether the name is free, and it is not legal clearance.