They're commonly called "deadbeats" — people who refuse to support their families after courts order them to pay — and CBC News has learned they owe more than $3.7 billion across the country for support orders.
Nearly two-thirds of all support orders in Canada are in arrears.
In Ontario that number jumps to 80 per cent, although the provincial government says it has replaced an outdated computer system, and officials have collected more than $6.9 billion in support payments since 2003.
Experts and recipients say there aren't enough staff to do an adequate job of monitoring the nearly half a million open files across the country.
One debtor in Saskatchewan owes more than $580,000 in arrears. Prince Edward Island's worst debtor owes $240,000, and one delinquent in the Northwest Territories owes $238,000.
Rollie Thompson, a professor of law at Dalhousie University, says something needs to change.
"It's important to remember that every single one of these programs is seriously underfunded," he said. "There's no gold star program in Canada you can talk about."
CBC's data reveal there are just over 1,600 full-time jobs devoted to managing more than 470,000 open cases.
Caseloads range from a ratio of one employee to 233 cases in Quebec to 725 cases per employee in British Columbia.
"Politicians who talk big about families and children are the same people who aren't prepared to improve the staffing of maintenance enforcement programs," Thompson said.
Provincial maintenance enforcement programs started in the mid-1980s as a way to collect outstanding child and spousal support. The vast majority of cases referred are for child support.
Deadbeats are technically divorced partners, and experts say that 97 per cent are men.
Only three jurisdictions reveal their worst offenders, and two publish their photos online. The other provinces won't reveal the highest amount owing.
'Such a shame and waste,' says parent
In Manitoba, arrears topped $58 million as of August 2014. One parent, Lianna Anderson, 47, of Leaf Rapids, Man., is owed thousands of dollars from her ex-partner.
She thought it would be simple to collect once she registered with Manitoba's Maintenance Enforcement Office.
"I quickly found out that it sounds really good on paper," she said. "I find it to be such a shame and waste of taxpayers' dollars."
She hasn't received any payments from the maintenance enforcement program since last year, and the arrears keep building. Her complaints to the provincial enforcement office brought no results for months.
Manitoba's maintenance enforcement office finally sent her a letter apologizing for the lack of service in August.
"Basically, they didn’t even provide me the minimal level of service that they’re supposed to be," she said. "It’s disturbing."
Shauna Curtin, Manitoba's assistant deputy minister of justice, admits that sometimes errors do happen, but she says an officer is in place to review files.
"It's not a frequent occurrence, but when it does happen, we own responsibility for it," she said.
'A living nightmare'
All maintenance enforcement offices have ways of forcing deadbeat parents to pay, including garnishments, property seizures, taking away licences and even imposing jail time.
But Alan Little of Sasqualit, B.C., a father of three, says the system is too rigid and treats all payers as if they are deadbeats.
He has paid tens of thousands of dollars over the years for his children, but he lost his job and he got behind on child support.
"They don't stop the payments," he said. "It's never wiped off the books."
Since 1997, federal guidelines have determined how much parents need to pay for child support, but Little said problems arise when payers try to change orders to amounts they can afford.
His order is with the Nova Scotia provincial court, which told him it would take a year to get his case heard. He ended up on welfare at one point and had his driver's licence taken away.
"What I experienced was a living nightmare," he said.
Little is currently paying back his arrears now that he has a stable job in the Canadian navy, and he's in contact with his children every day.
Curtin said child support debt, unlike other debt, is never written off no matter how the payer's situation changes, and that could explain why arrears are so high.
"Something special about the debt owed to a former partner for child support is that it doesn't die," she said, "It lasts forever."
She added that maintenance enforcement programs are sometimes targeting people who can't afford to pay.
"We are administering a program on people who perhaps don't have lots of money," she said. "It's a matter of finding a way for the person to remain committed to supporting their children to the best of their ability."
Anderson said she doesn't understand why the office couldn't collect on her payments.
"I'm just angry and so disgusted with that office," she said. "It really upsets me."
Curtin said all offices are focused on recovering money. She points out that in Manitoba, $56 million in child support has flowed to families.
"All of the programs have the same objective, all of them." she said. "The idea is to get money to families."
Also on HuffPost: