Sorry it took me so long to respond. We had an unexpected death of someone in our church Sunday night, and it really knocked me out. Anyway, I will try to help you out, but I'm not familiar with EZ claim so it is hard for me to comment on that. Also, I've not used Office Ally so again I'm not familiar with the way they work. From the way you are explaining it, you need a software to prepare the claim file to be submitted to Office Ally, so it sounds like you may need both. As far as Box 33, that would be the practice that you are billing for's billing information. For example, if you are billing for Middleville Family Practice and the checks go to you then you would have:Middleville Family PracticeYour Street AddressYour City, State ZipBut if the checks still go to them then you would have:Middleville Family PracticeTheir Street AddressTheir City, State ZipAnd their tax ID goes in box 25, not yours. Your tax ID should never be on a claim. The money isn't being paid to you, but to the provider, even if the checks are mailed to you.Michele