Freezing a user comes down to one checkbox field, IsFrozen on the UserLogin object. Set it to true and the user can’t log in:
Id,IsFrozen
0Ywfj00000E7r9BCAR,true
To freeze user in Salesforce, click Freeze on the user record for one person, or update UserLogin rows with Data Loader, the CLI or Apex for many. Every recipe below was run in our Developer Edition org on November 4, 2026, unless it says otherwise.