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There are 4 levels - Off, Info, Warning or Error and these at default levels on the database.  However, if you want to change these, see below.

Opening the Database Object Setup Activity

Click on Database Object Setup Activity 

Viewing the Bill Messages

From the Object type dropdown, choose Bill Message Type

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Highlight the Bill Message and the right hand side of the screen will display the Name, Description, Minimum Severity Level an Current Severity Level 

Amending the Bill Messages

Click on the Bill Message 

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