In March 1991, a teenager from Kasese was sitting through a compulsory political training at Chwa II Memorial College, Kyankwanzi, waiting for his senior six results, when a guest speaker walked in.
The man was a commissioner of customs at Ministry of Finance, and he had come to talk to students about a new government idea: an agency that would soon be called Uganda Revenue Authority (URA).
He talked about responsibility. He talked about why every citizen owed something to the state they lived in.
Oscar Kambona was curious about exactly one thing: why is government sending ‘someone to talk to us about taxes?’ The answer, once he chased it down, surprised him.
Tax was law. No tax can be charged unless a law says so. And if it were law, then a lawyer, someone trained specifically to interpret law, was the natural person to be doing it, not an accountant.
‘That was the question I asked myself,’ he says. ‘Why is it that taxation is being left as a preserve of accountants?’
It is a small, sharp insight, and it would define the next 35 years.
He was a guest at the fifth edition of Tax Nights, a networking and knowledge-sharing event hosted by The Tax Hub UG in Kampala.
Three students
At Makerere University, three years into a law degree still taught as a three-year programme, a man named Prof David J. Bakibinga arrived as the first head of legal services at the newly formed URA and introduced a brand-new elective: revenue law and taxation.
At least 46 students were in Kambona’s class, but almost all of them avoided the unit; no notes existed, no track record of who passed, nothing but risk.
Three students signed up. Kambona, Robert Kabushenga, later the chief executive of Vision Group, and Benson Tusasirwe.
This is the kind of detail that looks, in hindsight, like destiny. It wasn’t. It was a teenager’s curiosity from a political training camp, refusing to let go, meeting an unlikely elective at exactly the right moment.
Kambona calls this combination ‘preparation meeting opportunity,’ and he repeats it so often across his career that it stops sounding like a platitude and starts sounding like an operating principle.
Opportunities, in his telling, are not rare. What is rare is being ready when one appears.
The classroom
At Law Development Centre (LDC), taxation was still being taught by an accountant because there were, at that point, no tax lawyers in the country at all.
Kambona finished his diploma, and LDC, short of anyone else qualified, asked him to stay on and teach the unit he had just studied.
He started lecturing on revenue law and taxation around 1995, and kept teaching for years.
The list of people who sat in his classroom reads like a directory of Uganda’s modern legal establishment. The Chief Justice. The Deputy Chief Justice. The Attorney General, whose final exam Kambona set.
The list also includes the Director of Public Prosecutions and members of the Tax Appeals Tribunal, including its current chairperson.
‘I can name right from the Chief Justice,’ he says, without much formality, because to him it is simply a record of who walked through a door he happened to be standing behind.
Years later, when Kambona pursued his own postgraduate studies, several of his former students, by then judges, professors, and senior practitioners, sat as his examiners.
The teacher became the candidate.
Second to file
In 1997, the Tax Appeals Tribunal was established to hear tax disputes outside ordinary courts. Parliament asked LDC’s law society for comments on the enabling legislation.
Kambona, the man teaching the only tax course in the building, was the obvious person to consult.
He studied the tribunal before it existed, advised on its design, and then, once it opened its doors, became one of its very first litigants.
The first person ever to file a case before the tribunal was an accountant. The second was Kambona.
The case was Uganda Consolidated Properties versus URA, and the dispute, on its surface, looked low-key.
A company had sold a building and not charged Value Added Tax (VAT), because the law exempted sales of land.
URA said a building isn’t land, so pay the tax. Kambona disagreed, and his argument came straight from a land law lecture most people forget the moment they pass the exam: a title deed doesn’t say ‘building,’ it says ‘land.’
A building is simply land with something standing on it. Sell the building, and you have sold the land beneath it.
He won, and the law itself absorbed the lesson. It was rewritten to exempt only the sale of undeveloped land specifically, closing the gap his argument had opened.
It is a recurring shape in Kambona’s career. He finds a layer nobody else notices, pulls on it in a courtroom, and the legislature eventually has to come back and patch the hole.
He did it again in the MultiChoice case, when URA tried to tax the satellite broadcaster for ‘importing’ a service from South Africa.
He argued that the importer of a broadcast signal is technically whoever’s dish receives it, which is every subscriber in their living room, not MultiChoice.
URA could hardly bill every Ugandan with a dish. The law had to be amended.
He also fought, repeatedly, over the requirement that taxpayers pay 30 percent of a disputed assessment before the tribunal would hear a case, arguing that ‘pending final resolution’ could mean any time before judgment, even the day before, not the moment of filing.
He lost that one in the Commercial Court, but the legislature noticed the wording gap and closed it anyway. Win or lose, the law kept rewriting itself around his arguments.
Know your lane
Kambona is fond of dividing his advice into neat clusters of principles that comprise connection, mindset, skill, ethics, or excellence, impact, and growth, which is the rhetorical habit of a man who spent two decades as a lecturer and never quite put the chalk down.
Beneath that is a genuinely unusual career decision he chose, early and deliberately, to specialise only in tax litigation, and to outsource everything else.
‘You must know your strength,’ he says. ‘My strength was in tax litigation. It was not necessarily in tax advisory.’
So, he built the Uganda Tax Bureau around a strict division of labour: audit firms would prepare objections and advisory work, and Kambona would step in only once a dispute reached the tribunal, using the accountants who had built the case as his expert witnesses.
He struck exactly this arrangement with PricewaterhouseCoopers (PwC), litigating the firm’s contested cases while their in-house team handled everything upstream.
It is, in management terms, an early and instinctive form of ‘stick to your lane and build alliances at the seams’, the same logic that underlies the modern fascination with comparative advantage, except Kambona arrived at it from a courtroom, not an economics textbook.
The arrangement produced an odd subplot: the PwC tax director he partnered with, a Swedish expatriate named Annebritt Aslund, was later appointed URA’s Commissioner General, meaning Kambona was suddenly asked to act for the very authority he had spent years suing.
He took on select cases, including the landmark Rabbo Enterprises versus URA, arguing, against the loud objection of fellow lawyers furious about a 30 percent prepayment rule, that tax disputes had to start at the tribunal, not the High Court.
The Court of Appeal disagreed with him. The Supreme Court eventually didn’t. Tax litigation now runs through the tribunal first because Kambona was willing to be unpopular long enough to be proven right.
‘I don’t care,’ he says, of taking the unpopular position. ‘Believe in your case … no matter the consequences.’
No names on the door
In 2001, a senior politician preparing to leave government for private practice, Bart Katureebe, later Chief Justice, called Kambona with an idea: a single law firm where a client with a tax problem, a land dispute, or a government matter could all be handled under one roof, without juggling specialists scattered across town.
Four lawyers, Katureebe, Kambona, Elly Karuhanga, and Sam Mayanja, debated what to call it. Law firms at the time were named after their founders.
The four men chose something generic, Kampala Associated Advocates, built to outlast any one partner’s name on the door.
The Uganda Law Council objected. The founders’ counter-argument was that you cannot keep naming a firm after individuals once it has 20 partners. KAA now has dozens.
What Kambona built inside it was less a tax department than an apprenticeship machine. He picked Bruce Musinguzi as a student at LDC, brought him in as an associate before he had even enrolled as an advocate, personally walked him through early appeals, and watched him become KAA’s tax partner.
‘He delegates,’ Kambona says of Musinguzi now, with evident pride, the same way a coach talks about a player who has taken over the position.
The lesson he draws from it is that lawyers don’t stay for money; they stay because they can see a route to partnership. Firms that can’t show that route lose their best people to firms of one.
Leader without a title
Underneath the case law and the firm-building sits a man who, late in a litigation career most lawyers would consider already accomplished enough, went back to school for a PhD, not on taxation alone, but on the relationship between tax enforcement and human rights.
This focuses on whether mistreating a taxpayer makes that taxpayer less likely to comply.
It is the kind of question only someone who has spent decades inside disputes would think to ask, because it isn’t really a legal question. It’s a question about trust.
He frames the decision through three self-chosen values: excellence, impact, and growth, and insists, carefully, that excellence is not perfection. ‘Perfection is in someone’s judgment,’ he says. ‘Excellence is striving to do the best you can.’
Kambona is of the view that you should master ‘first things first, get the job before you dream of the firm, and then let excellence, not the hunt for an unattainable flawlessness, be what keeps you in the room once you are in it.’
He describes himself as ‘a leader without a title.’ It is an odd thing for a senior partner with a PhD, a named seat at one of Uganda’s most prominent law firms, and three decades of jurisprudence behind him to insist on.
But it is consistent with everything else about him: the value was never the title. It was the seam in the law nobody else had noticed, the student nobody else thought worth teaching, the case nobody else believed could be won.
Kambona built a career by being the second person in the room, the third person in the class, the one undervalued subject nobody else wanted, and turning each into the thing he was known for.
‘Are you prepared?’ he asks, closing out the evening. ‘The opportunity is going to come. But are you prepared for it?’
It is, in the end, the same question a customs commissioner once put to a curious teenager in 1991, who happened to be listening.