First, the local service tax or LST applies to employees and self-employed people. If your client was an employee, then his employer should have already taken out the LST from his pay. If that is the case then there is no form to file, as the employer files the LST form and pays the LST tax that was deducted from the employees pay . If your client is self-employed, then he may have to pay the LST tax himself on a separate LST return, to the township where his place of business is at, but I am not sure of this, since I am not sure of the LST rules for self-employed people in all the different townships of Pennsylvania. I don't believe you can add LST to the wage tax return as I have never heard of this before. All of the aforementioned is as far as I know, but you should research this yourself as aforementioned is my opinion only.