It wasn't hard. All it took was a source of income that wasn't entirely on the radar of the Canada Revenue Agency — tips earned from waiting tables, for instance, or selling used cars on Craigslist.
Maybe they did day labour on construction sites, or flipped houses, or drove trucks or, ahem, wrote a few freelance articles.
Whatever the case, all that unreported income has contributed to Canada's underground economy — which, according to Statistics Canada, was worth about $35 billion in 2008, the most recent year for which numbers were available. In recent years, however, the Canada Revenue Agency has decided to try to rein in some of that undocumented economic activity.
The taxman put in a lot of overtime — in the wilds of B.C., on the construction sites of the Prairies and in the restaurants of southern Ontario — searching for unaccounted-for cash in sectors where the bookkeeping is less than precise.
A blitz of 145 serving staff in St. Catharines, Ont., turned up $1.7 million in unreported tips.
In Winnipeg, Regina and Saskatoon, the CRA found $339,000 in unpaid taxes among sub-contractors who did home renovation work in association with big retail stores.
And in Yukon and northern B.C., a two-year examination uncovered almost $2 million in unpaid taxes among hundreds of small-time workers providing services associated with the region's oil and gas boom. These included drivers, first aid personnel, "hot shot" couriers who deliver material to often-remote locations. Many of these were transient workers who lived out their cars for weeks on end, found work through word of mouth and operated in isolated areas reachable only by off-road vehicles.
"It can be very challenging to meet with them," said an internal CRA report on the crackdown from May 2012, obtained by The Canadian Press under the Access to Information Act.
On top of the recovered tax revenue, the CRA also levied another half-million dollars in fines and interest, but the agency did not pursue criminal charges in the B.C. and Yukon cases.
All of which adds up to, if not a lot of money in federal government terms, a shot across the bow of other middle-income tax cheats.
"I think the message CRA is trying to get out there is a warning to people that this type of non-reported income is a problem," said Jamie Golombek, managing director of tax estate planning at CIBC Wealth Advisory Services.
"They're not necessarily collecting huge amounts of money … but I think it sends a very strong message."
CRA working off tips, 'lifestyle audits'
The CRA remains tight-lipped about how, exactly, it finds all this undocumented cash, but in a statement to CBC News, the agency said its investigative tools include, "leads from taxpayers, information-sharing agreements, spot visits by auditors, information obtained from third-party reporting systems, specialized computer software, leads from other audit files and lifestyle audits."
"To make sure businesses have calculated their taxes correctly, the CRA selects files to audit that represent a higher risk of non-compliance," the agency said.
The CRA has previously cracked down on other kinds of tax evasion, typically found among higher-income brackets, such as offshore bank accounts and other tax shelters.
The record suggests it gets results. Interest in charitable donation tax shelters has, for instance, dropped precipitously since CRA put them under the microscope a few years ago, according to Golombek.
"You really don't see them anymore," he said. "Especially this [tax] season. I think I've had maybe one inquiry."
The underground economy is not a big slice of Canada's financial pie. At $35 billion, it's about two per cent of the gross domestic product — "chump change" in the words of one expert — though Statistics Canada estimates don't take into account money produced by criminal activity such as drug dealing.
So, the numbers are "a little bit deceptive," said Stephen Easton, a professor of economics at Simon Fraser University in Burnaby, B.C. "There's plenty of illegal income out there but … it leaks back into the economy, even though it doesn't get taxed."
The CRA says it does not make a distinction between tax evasion linked to legal pursuits and that connected to criminal activity.
"All forms of tax evasion are criminal," the agency said.
That said, the agency does not always pursue criminal charges even when it finds hidden income. The decision to go to court is complicated, the CRA said.
Tough economy, sporadic work
The underground economy is a bigger phenomenon in the U.S., coming in at $2 trillion US, or 12 per cent of the GDP, according to one recent study. Estimates for countries like Greece, Kazakhstan and Armenia say as much as one-quarter of those countries' GDP is off the books.
Economic downturns and high tax rates are among the factors that lead people to seek under-the-table income, say experts. It has also been suggested that today's younger workers are less likely to seek traditional employment, which some see as confining, in favour of more loosely structured jobs (freelance graphic designer, artisanal baker, etc.) that are also less likely to have strictly documented payrolls.
"It's much more an issue of personal circumstance," said Golombek. "The economy has been tough, housing prices have been rising. Work is sporadic, and people feel they need to keep the cash."
"It may be tempting for some to receive cash or non-traceable income, but it's really doing a disservice to the entire taxpayer base, because it just means everybody else has to pay more."