As some people here might remember, my father was a tax preparer (as EA and not as a CPA; he also was a Labor Negotiator) and a Lacerte user; but for accounting, he used Quicken. He used it for his own entity and for taking client paperwork and building their tax year. That's why it matters what you intend to be offering as your service. That's my point. It's like any set of tools; a plumber and an electrician have a few tools in common, and many specific to their own profession.