LastPass - How Do I Get LastPass to Auto-Fill the Right Credentials (Add Sub-Domains)?
How to add sub-domains (e.g. doit.wisc.edu is a sub-domain of wisc.edu) to your LastPass URL rules to help ensure that LastPass auto-fills the right credentials.
1. Go your LastPass Vault.
2. Click on the Account Settings (Gear icon) in the lower-left corner of the Vault.
3. Navigate to the URL Rules tab and Click Add.
4. Add the sub-domain to the list.
You also have the option of adding the hostname of a server/site or the full URL path to a website for more specific matching. In the case of the full URL path, this could help prevent phishing attacks, because LastPass will only auto-fill on an exact match. Spoofed (faked) URLs will not be an exact match.
For more information on using URL rules in LastPass to disable auto-fill for certain sites, refer to the LastPass (LogMeIn) article: Manage Never URLs.