When creating a signing order, the system's default validation for personal number input while searching for citizens is set to accept formats such as YYYYMMDDXXXXX, YYYYMMDD-XXXX or YYYYMMDD XXXX. 

However, if you need to restrict the format to only accept YYYYMMDDXXX, you can set validateSwedishPersonalNumberFormat to true in overlay/settings/config.json.

{
  "validateSwedishPersonalNumberFormat": true 
}