Checking for ApplicationName in a transaction through a Before Trigger I would like to be able to build a trigger that checks the ApplicationName coming across on a transaction, and if the ApplicationName is of a certain value, then I want to throw an error, saying the user is not allowed to make this transaction.

Is there a way to create this script?
Yes, you can use the APP_NAME() function in SQL.

This is set in the connection string though so it isn't reliable

Why not limit users? If a user has permissions, they can run msqry32 which is on any PC with Office installed, set a connection string using ODBC and make it look like what they want...