This is what I get when I want to save a bill: One or more charge lines do not have a tax code associated with it. Please assign a tax code for those lines.

Hello @karen770 ,

Have you ensured that you do have a proper tax code in the Sales Tax field in the Bill entry?  See below:

If these fields are empty, you will not be able to save the Bill.  Or if you have typed something other than the codes presented to you in the dropdown list to choose from, you should get a message popping up that says "Please make a valid entry".

As far as I know there are no other reasons why you would get this error message upon trying to save.

Hope this helps . . . good luck!