I don't know about the US system other than described in the article, but based on the UK system, where HMRC (our IRS-equivalent) supplies its own free-to-use w

I don't know about the US system other than described in the article, but based on the UK system, where HMRC (our IRS-equivalent) supplies its own free-to-use web application, I can think of two possible reasons that third-party software could be worth paying for: - improved usability - requiring certain form pages that are not provided in the government's own solution (HMRC web filing covers most, but not all, use cases - if you fall under one of the edge cases, as I did last year, you have a choice of filing on paper - requiring hand calculations, and a much earlier deadline - or paying for a COTS solution)