Login Error 3606: [AuthValidate] Failed to Validate User
Find out what to do if you get Care Identity Service error 3606 when trying to authenticate.
The issue
When trying to log in you see this error:
Login Error 3606: [AuthValidate] Failed to Validate User
It may look like the image below.
![Login Error 3606: [AuthValidate] Failed to Validate User](/binaries/content/gallery/website/services/care-identity-service/3606-error.jpg)
Possible causes
- You are logging in to a different environment to that which is set in your registry (usually experienced by testers, developers and other specialist users).
- The user profile has been closed.
- You have renewed your smartcard certificates and this error has begun to occur.
What to do: smartcard users
If you are using an Imprivata or Isosec smartcard
These smartcards are not supported by NHS England. You should contact your local IT team for help.
All other smartcards
You will need to get support from your local IT team. Depending on your organisation, this may be through your IT helpdesk, or via a dedicated Registration Authority team.
Each organisation is set up differently, so we cannot provide contact details that work for everyone. Check your intranet for links to an IT helpdesk, Registration Authority or smartcard team.
Last edited: 29 May 2026 9:30 am