Right. Turbo Tax is for self prepared returns and can't be used by paid preparers.
You can not use the Online versions or the Desktop Software to prepare returns for clients. Intuit has 2 products for tax preparers. They are Lacerte and ProSeries. ProSeries is the least expensive. You can install ProSeries and Turbo Tax on the same computer.
Intuit Products for Tax Professionals,
Desktop End User License Agreement
Scroll way down under
B Additional Terms
2. Supplemental License Grant and Restrictions.
C. Additional Restrictions
You are not licensed or permitted to use the Software, or to allow the Software to be used, to prepare tax returns, schedules or worksheets on a professional or commercial basis (i.e., for a preparer's or other fee or consideration). Additionally, if you violate these terms, you agree you must indemnify and defend Intuit against any claims or lawsuits, including (without limitation) attorneys’ fees, that arise from or result from the unlicensed use of the Software on a professional or commercial basis.
Online Terms of Service
See Section B Additional Terms
1.3 No Professional Use.You may not use the Services to prepare tax returns, schedules or worksheets on a professional or commercial basis (i.e., for a preparer's or other fee or consideration).