Every trial balance run this morning, in every firm in America, follows a method first set down in print in Renaissance Venice. That fact gets repeated at accounting conferences as trivia. It shouldn’t. Read the history straight through and a pattern shows up, and it matters to anyone working in this profession or investing in it. Accounting doesn’t change when accountants change. It changes when information technology changes. Each time it does, a new set of dominant companies gets minted.

Here is that history, in four technologies, and a fifth now arriving.

The friar who gave accounting to the world

One disclosure first. My co-founder and I named our tax technology company, Luca IQ, after this man. So I’m not a neutral party on the question of how much he mattered.

Start with the man himself, because he deserves better than the trivia treatment. Luca Pacioli was one of the great minds of the Renaissance. He was a Franciscan friar and a mathematician. He taught in the university cities of Italy. He befriended Leonardo da Vinci at the court of Milan, where Pacioli taught mathematics alongside Leonardo, and Leonardo drew the illustrations for Pacioli’s later book on the golden ratio. His masterwork was the Summa de arithmetica, printed in Venice in 1494. It ran roughly 615 pages, one of the earliest mathematical works ever produced on a printing press. It was also one of the first printed works on algebra written in the vernacular. Buried inside it was a 27-page section on bookkeeping. Those 27 pages went on to matter more than the other 588 combined.

Here is what makes Pacioli great, and it’s worth getting exactly right. Pacioli pioneered double-entry bookkeeping. Venetian and Tuscan merchants had been refining the practice for two centuries. He worked out its logic, turned it into a complete method, and put it into print for the first time. Pieces of it had circulated privately before him and gone nowhere. A merchant named Benedetto Cotrugli described some of the same methods in a 1458 manuscript. It went unpublished and achieved nothing close to the Summa’s influence. Codification was the bottleneck, not arithmetic. The method existed in fragments. It was on track to stay what it had been for two hundred years, a trade secret of the Italian merchant class. Pacioli saw that a merchant’s working practice belonged next to Euclid and algebra in the great mathematics text of his age. Then he made the radical choice. He wrote it in plain Italian instead of scholarly Latin, with worked examples, so that working merchants and not just academics could actually use it. He took knowledge that was privately held and handed it to the world.

That is the rarer kind of achievement. History is full of people who devised better methods that died with them. It has very few who changed how the entire world works. Pacioli’s treatise became the basis for bookkeeping manuals for at least the next century. More than five hundred years later, every balance sheet on earth still runs on his system. Debits are on the left because Luca Pacioli put them there. He is known as the father of accounting. That title is not honorific inflation. It is a job description that has never needed a successor.

The friar part was not decoration. Pacioli studied theology and took vows in the Order of Friars Minor sometime in the 1470s. He stayed inside the Church for the rest of his life. It was not always smooth. His order barred him from teaching the young men of his hometown in 1491, apparently out of jealousy over privileges the Pope had granted him. Two years later the same town invited him back to preach the Lenten sermons. That was the year before the Summa went to press. He rose in the order, too. In 1504 he was offered the leadership of every Franciscan house in the province of Romagna, and turned it down. In 1510 he was made commissary of the monastery at Sansepolcro. In 1514, near the end of his life, Pope Leo X put him on the roll of the pontifical university in Rome. He was a friar for roughly forty of his seventy years. He wrote the Summa in the years he spent back at his order’s house in Sansepolcro. This was not a mathematician who happened to wear a habit.

And notice his mechanism, because it is the founding move of this entire industry. Pacioli took the profession’s essential knowledge. He paired it with the newest information technology on earth, a printing press less than fifty years old. Then he shipped it to everyone at once. Every accounting giant born in the five centuries since has been running that playbook, whether they know it or not.

The income tax and the loose-leaf binder

For its first four hundred years after Pacioli, accounting was a craft, not an industry. The profession we know was built by law. Scotland chartered the first accountancy bodies in the 1850s. New York passed the first American CPA statute in 1896. Then two acts of Congress created permanent, mandatory demand. The Revenue Act of 1913 established the modern federal income tax. The securities laws of 1933 and 1934 required audited financial statements from public companies.

The 1913 income tax also created the industry’s first great information company. Commerce Clearing House traces its founding to 1892. It has been publishing on U.S. tax law since the income tax began in 1913. Its affiliated Corporation Trust Company saw the tax bill coming while Congress was still debating it. By December 1913 it had signed up 1,000 subscribers to its first Income Tax Reporter. The binder ran 400 loose-leaf pages summarizing the new law, with room to swap in updated pages as courts and regulators ruled.

Stop on that detail, because it’s the whole business model of the modern industry in embryo. The loose-leaf binder was an information technology. Content that updates continuously, sold as a subscription, where canceling means falling out of compliance. CCH was running recurring-revenue software economics nearly ninety years before anyone said “SaaS.” It worked well enough that in 1995 Dutch publisher Wolters Kluwer bought Commerce Clearing House for nearly $2 billion. Today’s CCH Axcess platform is that 1913 binder’s direct descendant.

The microcomputer and three founders

The third technology shift arrived in the late 1970s, when computers got small and cheap enough for a tax office. Three founders from this window still define professional tax software today.

In Franklin, North Carolina, a former high school math teacher named Phil Drake joined his father’s tax practice. He decided pencil-and-calculator preparation was absurd. In 1977 he bought an IBM computer for $22,385 with borrowed money. His father mortgaged a piece of property to cover it. Drake programmed it himself and began selling the software to other accountants. Then the IRS launched electronic filing in 1986, and Drake transmitted some of the first e-filed returns in North Carolina. That early bet became the company’s moat. Drake Software is still private and still headquartered in Franklin. It today serves more than 70,000 firms filing over 40 million returns a year, by the company’s own count.

In Long Beach, California, a CPA named Larry Lacerte started building professional tax software in his garage in 1978. It became the standard for complex returns. The company later moved to Dallas. In San Diego, Michael Chipman of Chipsoft developed TurboTax in 1984. That one was aimed at taxpayers, not professionals. Both ended up inside the same company. Intuit acquired Chipsoft in 1993, and in 1998 bought Lacerte Software for roughly $400 million in cash. That gave Intuit the consumer market and the professional market at once.

The research-and-software conglomerates consolidated the same way. The Thomson Corporation spent the 1990s and 2000s assembling a tax and accounting division. It combined Creative Solutions, maker of what became UltraTax CS, with the research publishers RIA and PPC. Then it merged with Reuters in 2008 to form Thomson Reuters. Wolters Kluwer had CCH. Intuit had Lacerte, ProSeries, and TurboTax. By the 2000s, the microcomputer generation’s startups had become the industry’s permanent landlords.

The pattern, and why it matters now

Line the eras up and the rhythm is hard to miss. Pacioli seized the printing press. CCH seized the income tax and the loose-leaf binder. Drake, Lacerte, and TurboTax seized the microcomputer. The e-file mandate and the internet turned those products into infrastructure. In every case, the winner was whoever moved the profession’s information onto the new medium first. Some of them came from inside the profession and some from outside, and that turned out not to matter. Expertise was never the scarce input. Said differently: the experts never lost to better experts. They lost to better distribution.

Bring that up to 2026 and the picture looks like what the pattern predicts. Returns reach the government through the IRS Modernized e-File system. No company can touch that system without IRS authorization as a software developer, a transmitter, or both. Research still sits in Checkpoint and CCH AnswerConnect, the direct descendants of RIA and the 1913 binder. Preparation still sits in UltraTax, Lacerte, ProSeries, Drake, and CCH Axcess. Every one of them is either a microcomputer-era product or owned by a company that bought one. That is five centuries of stacked distribution, and distribution is the real asset here. The medium underneath it is changing again, because software can now read a source document and write to a form. Nothing about that changes what a debit is. Pacioli settled that in 1494. What it changes is who owns the pipes.

Two conclusions follow, one comforting and one not, depending on where you sit.

The comforting one: this industry produces extraordinarily durable companies. The dominant platforms of 2026 trace their lineages back thirty years, fifty years, and in CCH’s case more than a century. Switching costs are brutal, the regulatory moat refills annually every time Congress amends the tax code, and the subscription economics CCH pioneered in a binder still print money. There are few sectors where market leadership survives this long.

The uncomfortable one: in five hundred years, leadership in this industry has changed hands at exactly the moments the underlying information technology changed. Essentially never in between. That is worth keeping in mind, because the medium is changing again right now. What the shift actually means for the profession, past the hype and the panic, is where this series goes next.

This is the third in a series on the accounting profession.